Class 10th

Direction: In the following questions, a statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as:
(a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
(b) Both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of
Assertion (A).
(c) Assertion (A) is true but Reason (R) is false.
(d) Assertion (A) is false but Reason (R) is true

Q.1. Assertion (A) : Tungsten metal is used for making filaments of incandescent lamps.
Reason (R) : The melting point of tungsten is very low.

Answer(c)

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Q.2. Assertion (A) : If a graph is plotted between the potential difference and the current flowing,
the graph is a straight line passing through the origin.
Reason (R) : The current is directly proportional to the potential difference.

Answer(a)

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Q.3. Assertion (A) : Longer wires have greater resistance and the smaller wires have lesser resistance.
Reason (R) : Resistance is inversely proportional to the length of the wire.

Answer(c)

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Q.4. Assertion (A) : Alloys are commonly used in electrical heating devices, like electrical iron,
toasters etc.
Reason (R) : Alloys do not oxidise (burn) readily at high temperatures.

Answer(a)

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Q.5. Assertion (A) : When the resistances are connected end-to-end consecutively, they are said to
be in series.
Reason (R) : In case the total resistance is to be increased, then the individual resistances are
connected in series.

Answer(b)

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Q.6. Assertion (A) : When the resistances are connected between the same two points, they are said
to be connected in parallel.
Reason (R) : In case the total resistance is to be decreased, then the individual resistances are
connected in parallel.

Answer(b)

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Q.7. Assertion (A) : A cell is a device which converts chemical energy into electrical energy.
Reason (R) : Cell maintains a constant potential difference between its terminals for a long
time.

Answer(b)

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Q.8. Assertion (A) : The resistivity of a substance does not depend on the nature of the substance
and temperature.
Reason (R) : The resistivity of a substance is a characteristic property of the material.

Answer(d)

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Q.9. Assertion(A) : Tungsten metal is used for making filaments of incandescent lamps.
Reason (R): The melting point of tungsten is very low.

Answer(c)

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Q.10. Assertion (A) : The fuse is placed in series with the device.
Reason (R) : Fuse consists of a piece of wire made of a metal or an alloy of appropriate melting
point.

Answer(b)

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Q.11. Assertion (A) : The coil of a heater is cut into two equal halves and only one of them is used into heater. The heater will now require half the time to produce the same amount of heat.
Reason (R) : The heat produced is directly proportional to square of current.

Answer(b)

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Q.12. Assertion (A) : The wires supplying current to an electric heater are not heated appreciably.
Reason (R) : Resistance of connecting wires is very small and H<< R.

Answer(a)

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Q.13. Assertion (A) : A current carrying wire should be charged.
Reason (R) : The current in a wire is due to flow of free electrons in a definite direction.

Answer(d)

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Q.14. Assertion (A) : Electron has a negative charge.
Reason (R) : Electrons move always from a region of higher potential to a region of lower potential.

Answer(c)

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Q.15. Assertion (A) : Heater wire must have high resistance and high melting point.
Reason (R) : If resistance is high, the electric conductivity will be less.

Answer(b)

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Q.16. Assertion (A) : In a chain of bulbs, 50 bulbs are joined in series. One bulb is removed now and circuit is completed again. If the remaining 49 bulbs are again connected in series across the same supply, then light
gets decreased in the room.
Reason (R) : Net resistance of 49 bulbs will be less than 50 bulbs.

Answer(d)

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Q.17. Assertion (A) : Fuse wire must have high resistance and low melting point.
Reason (R) : Fuse is used for small current flow only.

Answer(c)

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Q.18. Assertion (A) : The connecting wires are made of copper.
Reason (R) : The electrical conductivity of copper is high.

Answer(a)

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Q.19. Assertion (A) : Current is the rate of flow of charge.
Reason (R) : Electric current will not flow between two charged bodies when connected, if they are at same
potential.

Answer(b)

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Q.20. Assertion (A) : A bird perches on a high power line and nothing happens to the bird.
Reason (R) : The circuit is incomplete for the bird sitting on high power line.

Answer(a)

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Q.21. Assertion (A) : When a wire is stretched to three times of its length, its resistance becomes 9 times.
Reason (R) : Resistance is directly proportional to length of wire.

Answer(b)

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Q.22. Assertion (A) : It is advantageous to transmit electric power at high voltage.
Reason (R) : High voltage implies high current.

Answer(c)

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Q.23.Assertion (A) : Bending a wire does not affect electrical resistance.
Reason (R) : Resistance of a wire is proportional to resistivity of material.

Answer(b)

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Q.24. Assertion (A) : A voltmeter and ammeter can be used together to measure resistance but not power.
Reason (R) : Power is proportional to voltage and current.

Answer(d)

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Q.25. Assertion (A) : The 200 W bulbs glows with more brightness than 100 W bulbs.
Reason (R) : A 100 watt bulb has more resistance than a 200 W bulb.

Answer(b)

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Q.26. Assertion (A) : If 10 bulbs are connected in series and one bulb fused, then the remaining 9 bulbs will not work.
Reason (R) : Bulb of higher wattage will give less bright light.

Answer(b)

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Q.27. Assertion (A) : Good conductors of heat are also good conductors of electricity and vice versa.
Reason (R) : Mainly electrons are responsible for conduction.

Answer(a)

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Direction: In the following questions, a statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as:
(a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
(b) Both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of
Assertion (A).
(c) Assertion (A) is true but Reason (R) is false.
(d) Assertion (A) is false but Reason (R) is true

Q.1. Assertion(A) : White light is dispersed into its seven-colour components by a prism.
Reason (R) : Different colours of light bend through different angles with respect to the incident ray as they pass through a prism.

Answer(a)

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Q.2. Assertion(A) : The phenomenon of scattering of light by the colloidal particles gives rise to Tyndall effect.
Reason (R): The colour of the scattered light depends on the size of the scattering particles.

Answer(b)

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Q.3. Assertion(A): A normal human eye can clearly see all the objects beyond certain minimum distance.
Reason (R) : The human eye has capacity of adjusting the focal length of eye lens.

Answer(a)

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Q.4. Assertion(A) : A rainbow is sometimes seen in the sky in rainy season only when observer’s back is towards the Sun.
Reason (R) : Internal reflection in the water droplets cause dispersion and the final rays are in backward direction.

Answer(a)

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Q.5. Assertion (A) : Myopia is the defect of the eye in which only nearer objects are seen by the eye.
Reason (R) : The eye ball is elongated.

Answer(a)

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Q.6. Assertion(A): Hypermetropia is the defect of the eye in which only farther objects are seen.
Reason (R) : Hypermetropia is corrected by using converging lens.

Answer(b)

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Q.7. Assertion(A) : Danger signals are made of red colour.
Reason (R) : Velocity of red light in air is maximum, so signals are visible even in dark.

Answer(c)

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Q.8. Assertion(A): The sky looks dark and black instead of blue in outer space.
Reason (R) : No atmosphere containing air in the outer space to scatter sunlight.

Answer(a)

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Q.9. Assertion (A): The stars twinkle, while the planets do not.
Reason (R) : The stars are much bigger in size than the planets.

Answer(b)

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Q.10. Assertion(A): The Sun appears flattened at sunrise and sunset.
Reason (R) : The apparent flattering of the Sun’s disc at sunrise and sunset is due to atmospheric refraction.

Answer(a)

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Q.11. Assertion (A) : Blue colour of sky appears due to scattering of blue colour.
Reason (R) : Blue light has longer wavelength.

Answer(c)

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Direction: In the following questions, a statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as:
(a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
(b) Both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of
Assertion (A).
(c) Assertion (A) is true but Reason (R) is false.
(d) Assertion (A) is false but Reason (R) is true

Q.1. Assertion(A) : The centre of curvature is not a part of the mirror. It lies outside its reflecting surface.
Reason (R) : The reflecting surface of a spherical mirror forms a part of a sphere. This sphere has a centre.

Answer(a)

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Q.2. Assertion (A) : A ray passing through the centre of curvature of a concave mirror after reflection, is reflected back along the same path.
Reason (R) : The incident rays fall on the mirror along the normal to the reflecting surface.

Answer(a)

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Q.3. Assertion (A) : Light does not travel in the same direction in all the media.
Reason (R) : The speed of light does not change as it enters from one transparent medium to another.

Answer(c)

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Q.4. Assertion(A) : The emergent ray is parallel to the direction of the incident ray.
Reason (R) : The extent of bending of the ray of light at the opposite parallel faces (air- glass interface and glass-air interface) of the rectangular glass slab is equal and opposite.

Answer(a)

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Q.5. Assertion(A) : A ray of light travelling from a rarer medium to a denser medium slows down and bends away from the normal. When it travels from a denser medium to a rarer medium, it speeds up and bends towards the normal.
Reason (R) : The speed of light is higher in a rarer medium than a denser medium.

Answer(d)

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Q.6. Assertion(A): The mirrors used in search lights are concave spherical.
Reason (R) : In concave spherical mirror the image formed is always virtual.

Answer(c)

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Q.7. Assertion(A) : Light travels faster in glass than in air.
Reason (R) : Glass is denser than air.

Answer(d)

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Q.8. Assertion(A) : For observing traffic at back, the driver mirror is convex mirror.
Reason (R) : A convex mirror has much larger field of view than a plane mirror.

Answer(a)

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Q.9. Assertion(A) : Mirror formula can be applied to a plane mirror.
Reason (R) : A plane mirror is a spherical mirror of infinite focal length.

Answer(a)

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Q.10. Assertion(A) : It is not possible to see a virtual image by eye.
Reason (R): The rays that seem to emanate from a virtual image do not in fact emanates from the image.

Answer(d)

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Q.11. Assertion(A) : When the object moves with a velocity 2 m/s, its image in the plane mirror moves with a velocity of 4 m/s.
Reason (R) : The image formed by a plane mirror is as far behind the mirror as the object is in front of it.

Answer(a)

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Q.12. Assertion(A) : The height of an object is always considered positive.
Reason (R) : An object is always placed above the principal axis in this upward direction.

Answer(a)

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Q.13. Assertion(A) : Concave mirrors are used as make-up mirrors.
Reason (R) : When the face is held within the focus of a concave mirror, then a diminished image of the face is seen in the concave mirror.

Answer(c)

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Q.14. Assertion(A) : Refractive index has no units.
Reason (R) : The refractive index is a ratio of two similar quantities.

Answer(a)

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Q.15. Assertion(A) : The formula connecting u, v and f for a spherical mirror is valid in all situations for all spherical mirrors for all positions of the object.
Reason (R) : Laws of reflection are strictly valid for plane surfaces.

Answer(c)

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Q.16. Assertion(A): A person cannot see his image in a concave mirror, unless, he is standing beyond the center of curvature of the mirror.
Reason (R) : In a concave mirror, image formed is real provided the object is situated beyond its focus.

Answer(b)

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Q.17. Assertion(A): Virtual images are always erect.
Reason (R) : Virtual images are formed by diverging lenses only.

Answer(c)

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Direction: In the following questions, a statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as:
(a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
(b) Both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of
Assertion (A).
(c) Assertion (A) is true but Reason (R) is false.
(d) Assertion (A) is false but Reason (R) is true

Q.1. Assertion(A): A geneticist crossed two pea plants and got 50% tall and 50% dwarf in the progeny.
Reason (R) : One plant was heterozygous tall and the other was dwarf.

AnswerAnswer: (a)

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Q.2. Assertion(A) : Variations are seen in offspring produced by sexual reproduction.
Reason (R) : DNA molecule generated by replication is not exactly identical to original DNA.

AnswerAnswer: (a)

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Q.3. Assertion(A) : Mutation is sudden change in the genetic material.
Reason (R) : Variation is useful for the survival of species over time.

AnswerAnswer: (b)

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Q.4. Assertion(A): Mendel selected the pea plant for his experiments.
Reason (R) : Pea plant is cross-pollinating and has unisexual flowers.

AnswerAnswer: (a)

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Q.5. Assertion(A): The sex of a child is determined by the mother.
Reason (R) : Humans have two types of sex chromosomes: XX and XY.

AnswerAnswer: (d)

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Q.6. Assertion(A) : Evolution is an extremely slow process.
Reason (R) : New characters are accumulated in an organism during its lifetime.

AnswerAnswer: (c)

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Q.7. Assertion(A) : According to Darwin, all organisms compete with each other for existence.
Reason (R) : During the struggle for existence there is survival of the fittest.

AnswerAnswer: (b)

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Q.8. Assertion(A) : Geographical isolation cannot be a major factor in speciation of an asexually reproducing organism.
Reason (R) : Asexually reproducing organisms do not require any other organism for reproduction.

AnswerAnswer: (a)

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Q.9. Assertion : In humans, height is a trait which shows variation.
Reason: Some humans are very tall, some have medium height whereas others are short heighted.

AnswerAnswer: (b)

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Q.10. Assertion : Accumulation of variation in a species increases the chances of its survival in changing environment.
Reason : Accumulation of heat resistance in some bacteria ensure their survival even when temperature in
environment rises too much.

AnswerAnswer: (b)

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Q.11. Assertion : Traits like tallness and dwarfness in pea plant are inherited independently.
Reason: When a homozygous tall pea plant is crossed with dwarf pea plant, medium sized pea plant is obtained in F, generation.

AnswerAnswer: (c) Traits like tallness and dwarfness in pea plant are inherited independently and when a homozygous tall pea plant is crossed with a dwarf pea plant, only tall pea plants are obtained in F1 generation.

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Q.12. Assertion : Pea plant is considered ideal for hybridisation experiments.
Reason: Pea is self pollinating plant with short life cycle and bears visible contrasting traits.

AnswerAnswer: (a) Mendel chose pea plants for studying inheritance because of number of reasons. Pea plants are self pollinating which enables them to produce next generation of plants easily, also purelines could be easily obtained. Due to short life cycle, many generations of pea plants can be produced in a comparatively short span of time. Also pea plants shows a number of clear cut visible contrasting traits like tall and dwarf height, round and winkled seeds, etc.

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Q.13. Assertion : Monohybrid cross deals with inheritance of one pair of contrasting characters.
Reason: Dihybrid cross deals with inheritance of two pairs of contrasting characters.

AnswerAnswer: (b)

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Q.14. Assertion : When pea plants (pureline) having round yellow seeds are crossed with pureline plants having wrinkled green seeds, then all pea plants obtained in F, generation bear wrinkled green seeds.
Reason: Round and yellow seeds are dominant to wrinkled and green seeds.

AnswerAnswer: (d)

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Q.15. Assertion: If blood group of both mother and father is O then the blood group of children will also be O.
Reason: Blood group in humans is determined by many alleles of a gene viz. I^A, I^B, I⁰.

AnswerAnswer: (b)

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Q.16. Assertion: In some reptiles, the temperature at which fertilised egg is incubated before hatching plays a role in determining sex of offspring.
Reason: In turtle, high incubation temperature above 33°C leads to development of female offspring whereas in lizards high incubation temperature results in male offspring.

AnswerAnswer: (b)

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Q.17. Assertion : In humans, male (or father) is responsible for sex of the baby which is born.
Reason: Y chromosomes are present in only male gametes or sperms.

AnswerAnswer: (a)

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Q.18. Assertion: If mother is homozygous for black hair and father has red hair then their child can inherit black hair.
Reason: Gene for black hair is recessive to gene for red hair in humans.

AnswerAnswer: (c)

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Q.19. Assertion : Selfing of a plant for several generations helps plant breeders to obtain pure breeding varieties.
Reason: Pure breeding plants are heterozygous for many traits.

AnswerAnswer: (c)

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Q.20. Assertion : A tall plant which always produces tall offsprings is considered heterozygous for height and is represented by genotype (Tt).
Reason: A tall plant which always produces tall offspring is homozygous dominant and will always produce
only one type of gamete (T).

AnswerAnswer: (d)

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Q.21. Assertion : A geneticist crossed two plants and got 50% tall and 50% dwarf progenies.
Reason: This cross follows Mendelian law as one of the parent plant might be heterozygous.

AnswerAnswer: (b)

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Q.22. Assertion : A heterozygous tall plant when crossed with homozygous dwarf plant will produce tall and
dwarf plants in the ratio of 3:1.
Reason : A heterozygous tall plant will produce two types of gametes, i.e., one with T and other with t whereas homozygous dwarf plant produce all gametes with t only.

AnswerAnswer: (d)

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Q.23. Assertion : In human males all the chromosomes are perfectly paired except X and Y chromosomes.
Reason: X and Y are sex chromosomes.

AnswerAnswer: (a)

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Q.24. Assertion: A child which has inherited X chromosome from father will develop into a girl child.
Reason: Girl child inherits X chromosome from father and Y chromosome from mother.

AnswerAnswer: (c)

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Q.25. Assertion : Genes present in every cell of an organism control the traits of the organisms.
Reason: Gene is specific segment of DNA occupying specific position on a chromosome.

AnswerAnswer: (b)

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Q.26. Assertion : In grasshoppers, females are heterogametic and males are homogametic.
Reason: In grasshoppers, male has only one sex chromosome (XO) whereas the female has sex chromosomes
(XX).

AnswerAnswer: (d)

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Q.27. Assertion : Round green seeds in pea can be represented by RRyy of Rryy.
Reason: Round yellow seeds and green wrinkled seeds are parental combinations whereas round green and
wrinkled yellow are recombinants.

AnswerAnswer: (b)

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Q.28. Assertion: If mother has two dominant alleles for black hair and father has two recessive alleles for blonde hair then their child will inherit one dominant allele from mother and one recessive allele from father and will have black hair.
Reason: Progeny inherits one genes for each trait from its parents but the trait shown by progeny depends on inherited alleles

AnswerAnswer: (a)

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Direction: In the following questions, a statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as:
(a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
(b) Both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of
Assertion (A).
(c) Assertion (A) is true but Reason (R) is false.
(d) Assertion (A) is false but Reason (R) is true

i.) Assertion: A bisexual flower produces ova as well as pollen.

Reason: Ova and pollen are produced in the carpel.

Answer – (c) A is true but R is false

ii) Assertion: Female produces two types of gametes.

Reason: Female has two X chromosomes..

Answer – (d) A is false but R is true

iii) Assertion: Height in pea plants is controlled by efficiency of enzymes and is thus genetically controlled.

Reason: Cellular DNA is the information source for making proteins in the cell.

Answer: (a) Both A and R are true and R is the correct explanation of A

IV) Assertion (A): Offsprings produced by sexual reproduction show variation.

Reason (R): Each offspring produced by sexual reproduction inherits all the genes from
each parent.

Answer: C. A is true, but R is false

5) Assertion: Probability of survival of an organism produced through sexual reproduction is more than that of organism produced through asexual mode.

Reason: Variations provide advantages to individuals for survival.

Answer: a) Both A and R are true and R is the correct explanation of A

Q.1. Assertion(A) : Asexual reproduction is a primitive type of reproduction.
Reason (R) : Asexual reproduction involves only mitotic cell division.

Answer(a)

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Q.2. Assertion(A) : Spores are unicellular bodies.
Reason (R) : The parent body simply breaks up into smaller pieces on maturation.

Answer(c)

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Q.3. Assertion(A) : Clones are offspring of an organism formed by asexual reproduction.
Reason (R) : Clones have exact copies of DNA as their parent.

Answer(b)

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Q.4. Assertion(A) : Colonies of yeast multiply in sugar solution.
Reason (R) : Sugar is made of sucrose which provides energy for sustaining all life activities.

Answer(a)

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Q.5. Assertion(A): Pollen grains from the carpel stick to the stigma of stamen.
Reason (R) : The fertilised egg cells grow inside the ovules and become seeds.

Answer(d)

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Q.6. Assertion(A) : The offspring produced by sexual reproduction is likely to adjust better in environmental fluctuation.
Reason (R) : During the fusion of gametes there is mixing of genetic material from two parents.

Answer(a)

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Q.7. Assertion(A) : Growth hormone stimulates the growth of different body parts.
Reason (R) : Gonadotropins stimulate the production of sex hormones.

Answer (B)

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Q.8. Assertion(A): Testes lie in penis outside the body.
Reason (R) : Sperms require temperature lower than the body temperature for development

Answer(d)

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Direction: In the following questions, a statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as:
(a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
(b) Both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of
Assertion (A).
(c) Assertion (A) is true but Reason (R) is false.
(d) Assertion (A) is false but Reason (R) is true

Q.1. Assertion(A) : Insulin regulates blood sugar level.
Reason (R) : Insufficient secretion of insulin will cause diabetes.

Answer(a)

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Q.2. Assertion(A) : Animals can react to stimuli in different ways.
Reason (R) : All animals have a nervous system and an endocrine system involving hormones.

Answer(a)

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Q.3. Assertion(A): The effect of auxin hormone on the growth of root is exactly opposite to that on a stem.
Reason (R) : Auxin hormone increases the rate of growth in root and decreases the rate of growth in stem.

Answer(c)

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Q.4. Assertion(A): A receptor is a specialized group of cells in a sense organ that perceive a particular type of stimulus.
Reason (R) : Different sense organs have different receptors for detecting stimuli.

Answer(b)

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Q.5. Assertion(A): Cyton region of nerve fibre collects information for the brain.
Reason (R): Nerve fibres can either have or lack myelin sheath.

Answer(d)

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Q.6. Assertion(A): A nerve impulse is an electrochemical event.
Reason (R) : In a nerve impulse there are changes in the resting potential which spreads down the nerve fibre.

Answer(a)

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Q.7. Assertion(A) : The brain is also known as the central nervous system.
Reason (R) : Central nervous system controls and regulates the voluntary actions.

Answer(d)

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Q.8. Assertion(A) : The spinal nerves are 31 in number.
Reason (R) : Spinal nerves only have sensory neurons in them

Answer(c)

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Q.9. Assertion (A) : Insulin regulates blood sugar level.

Reason (R) : Insufficient secretion of insulin will cause diabetes.

Answer (A)

Q.10. Assertion(A): A growing plant appears to bend towards the direction of light

Reason (R) : The plant hormone auxin diffuses towards the shady side of the root.

Answer (A)

Q.11. Assertion (A) : The effect of auxin hormone on the growth of root is exactly opposite to that on a stem.

Reason (R) : Auxin hormone increases the rate of growth in root and decreases the rate of growth in stem.

Answer (C)

Q.12. Assertion(A) : The use of iodised salt prevents risk of goitre.

Reason (R) : Iodised salt provides iodine needed by thyroid gland to make sufficient thyroxin for our body.

Answer (A)

Q.13. Assertion (A) : The brain is also known as the central nervous system.

Reason (R) : Central nervous system controls and regulates the voluntary actions.

Answer (D)

Q.14. Assertion (A) : Animals can react to stimuli in different ways.

Reason (R) : All animals have a nervous system and an endocrine system involving hormones.

Answer (A)

Q.15. Assertion (A) : A receptor is a specialized group of cells in a sense organ that perceive a particular type of stimulus.

Reason (R) : Different sense organs have different receptors for detecting stimuli.

Answer (B)

Direction: In the following questions, a statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as:
(a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
(b) Both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of
Assertion (A).
(c) Assertion (A) is true but Reason (R) is false.
(d) Assertion (A) is false but Reason (R) is true

Q.1. Assertion (A) : Plants lack excretory organs.
Reason (R) : Plants usually absorb essential nutrients.

Answer(b)

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Q.2. Assertion (A) : In anaerobic respiration, one of the end product is alcohol.
Reason (R) : There is an incomplete breakdown of glucose.

Answer(a)

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Q.3. Assertion (A) : In plants there is no need of specialised respiratory organs.
Reason (R) : Plants do not have great demands of gaseous exchange.

Answer(a)

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Q.4. Assertion (A) : Bile is essential for digestion of lipids.
Reason (R) : Bile juice contains enzymes.

Answer(c)

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Q.5. Assertion (A) : Carbohydrate digestion mainly takes place in small intestine.
Reason (R) : Pancreatic juice contains the enzyme lactase.

Answer(c)

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Q.6. Assertion (A) : Aerobic respiration requires less energy as compared to anaerobic respiration.
Reason (R) : Mitochondria is the powerhouse of the cell.

Answer(d)

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Q.7. Assertion (A): Arteries are thick-walled and elastic in nature.
Reason (R) : Arteries have to transport blood away from the heart.

Answer(b)

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Q.8. Assertion (A) : Human heart is four-chambered.
Reason (R) : Vena cava is the only artery that supplies deoxygenated blood to the heart.

Answer(c)

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Q.9. Assertion (A): Energy is required to carry out different life processes.
Reason (R) : Energy is obtained in the form of ATP in the mitochondria.

Answer(a)

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Q.10. Assertion (A): Rings of cartilage are present in the throat,
Reason (R) : These ensure that the air-passage does not collapse

Answer(a)

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Q.11. Assertion (A): Pyruvate is a six-carbon molecule
Reason (R) : It is prepared in the cytoplasm as the first step to cellular respiration

Answer(d)

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Q.12. Assertion (A): Molecular movements are needed for life.
Reason (R): Body structures made up of these molecules need continuous repair and maintenance

Answer(a)

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Q.13. Assertion (A): Diffusion does not meet high energy requirements of multi-cellular organisms
Reason (R) : Diffusion is a fast process but occurs at the surface of the body.

Answer(c)

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Q.14. Assertion (A): The opening and closing of the pore is a function of the guard cells.
Reason (R) : Stomatal pores are the site for exchange of gases by diffusion.

Answer(b)

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Q.15. Assertion (A): The purpose of making urine is to filter out undigested food from intestine
Reason (R): Kidneys filter the waste and produce urine,

Answer(d)

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Q.16. Assertion (A): The inner lining of the small intestine has numerous finger-like projections called villi.
Reason (R) : The villi increase the surface area for absorption.

Answer(a)

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Q.17. Assertion (A): In human beings, the respiratory pigment is haemoglobin
Reason (R) : It is a type of protein which has high-affinity carbon dioxide.

Answer(c)

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Q.18. Assertion : The plants store some of the waste products in their body parts.
Reason: Raphides are the solid waste products of plants.

Answer(b)

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Q.19. Assertion : The movement of water and dissolved salts in xylem is always upwards.
Reason: ‘The upward movement of water is due to low pressure created by transpiration.

Answer(a)

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Q.20. Assertion : Photosynthesis takes place in green parts of the plants.
Reason: Photosynthesis always takes place in leaves.

Answer(c)

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Q.21. Assertion: The average number of heart beat of a person at rest is about 80 per minute.
Reason: One contraction and relaxation of the heart constitutes a complete heart beat.

Answer(d)

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Q.22. Assertion : Ureters are the tubes which carry urine from kidneys to the bladder.
Reason: Urine is stored in the urethra.

Answer(c)

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Q.23. Assertion : Ventricles have thicker walls than auricles.
Reason: Ventricles have to pump blood into various organs with great pressure

Answer(a)

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Q.24. Assertion : Capillaries are the thinnest blood vessels.
Reason: Capillaries connect the branches of arteries and veins.

Answer(b)

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Q.25. Assertion : Blood takes up oxygen from the alveolar air and release CO2 during exchange.
Reason: ‘The concentration of O, is more in alveolar air.

Answer(b)

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Q.26. Assertion: The large intestine is the largest part of the alimentary canal.
Reason: Tiger has a shorter small intestine, than herbivores.

Answer(d)

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Q.27. Assertion : Most of the living organisms carry out aerobic respiration.
Reason: Mitochondria is the site of aerobic respiration in the cell.

Answer(b)

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Q.28. Assertion : The Bowman’s capsule and the tubule together make a nephron.
Reason : The function of tubule is to allow the selective reabsorption of substances like glucose, amino
acids, urea, salts and water into the blood capillaries.

Answer(c)

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Q.29. Assertion : Pancreatic juice digests starch, proteins and fats.
Reason: Pancreatic juice contains digestive enzymes like pancreatic amylase, trypsin and lipase.

Answer (a)

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Q.30. Assertion: The accumulation of lactic acid in the muscles causes muscle cramps.
Reason: During vigorous physical exercise leg muscles respire anaerobically.

Answer(a)

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Q.31. Assertion : Phloem helps in translocation of food from the leaves.
Reason: Phloem provides mechanical support to plant.

Answer(c)

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Q.32. Assertion : Trachea does not collapse, when there is no air in it.
Reason : Trachea is supported by cartilage.

Answer(a)

Direction: In the following questions, a statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as:
(a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
(b) Both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of
Assertion (A).
(c) Assertion (A) is true but Reason (R) is false.
(d) Assertion (A) is false but Reason (R) is true

1.) Assertion: Lithium and Sodium both belong to same group.

Reason: Lithium and sodium both have same atomic number.

Answer – (c) Assertion is true but the Reason is false.

2.) Assertion: K shell of an atom can accommodate maximum 2 electrons.

Reason: K shell is always the outermost shell of an particular atom.

Answer – (c) Assertion is true but the Reason is false.

3.) Assertion: Elements having same number of valence shell are placed in same group.

Reason: In a group metallic character increases from Upper to Lower.

Answer – (b) The Assertion and the Reason are correct but the Reason is not the
correct explanation of the Assertion.

4.) Assertion: In a period as we move from left to right nature of oxides gradually changes from basic to acidic.

Reason: On moving left to right in a period non metallic character increases.

Answer – (a) Both the Assertion and the Reason are correct and the Reason is the
correct explanation of the Assertion.

5.) Assertion: The term atomic size refers to the radius of an atom.

Reason: Atomic size depends on – number of protons present in an atom.

Answer – (c) Assertion is true but the Reason is false.

6) Assertion (A) : Mendeléev concentrated on the compounds formed by elements with oxygen and hydrogen in his periodic table.
Reason (R) : Hydrogen and oxygen are very reactive and form compounds with most elements.

Answer(a)

7)Assertion (A) : In Mendeléev Periodic Table, cobalt was placed before nickel.
Reason (R): The atomic mass of cobalt is less than nickel.

Answer(c)

8) Assertion (A) : According to Mendeléev, the properties of elements are a periodic function of their atomic masses.
Reason (R) : Atomic number is equal to the number of protons.

Answer(b)

9) Assertion (A) : Noble gases have zero valency.
Reason (R) : Noble gases have stable electronic configuration.

Answer(a)

10) Assertion (A) : Elements in the same vertical column have similar properties.
Reason (R) : Elements have periodic dependence upon the atomic number.

Answer(b)

11) Assertion (A) : Silicon is a metalloid.
Reason (R) : Silicon shows only properties of non-metals.

Answer(c)

12) Assertion (A) : Fluorine has greater atomic radius than nitrogen.
Reason (R): Atomic radius decreases along a period.

Answer(d)

13)  Assertion (A): Li, Na, K form Döbereiner’s triads.
Reason (R) : Atomic mass of Na is roughly the average of atomic masses of Li and K.

Answer(a)

14) Assertion (A) : Magnesium belongs to 3rd period of modern periodic table.
Reason (R) : The valence electrons of magnesium is 2.

Answer(b)

15) Assertion (A) : Isotopes are placed together in the modern periodic table.
Reason (R) : Isotopes have same atomic number.

Answer(a)

Direction: In the following questions, a statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as:
(a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
(b) Both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of
Assertion (A).
(c) Assertion (A) is true but Reason (R) is false.
(d) Assertion (A) is false but Reason (R) is true

1) Assertion: Ethanoic acid liberates hydrogen with Sodium metal.

Reason: More reactive sodium displaces hydrogen from ethanoic acid.

Answer – (a) Both the Assertion and the Reason are correct and the Reason is the
correct explanation of the Assertion.

2) Assertion: Ethanoic acid reacts with ethyl alcohol in presence of conc H2SO4 to form ethyl ethanoate.

Reason: Esters are used in ice creams and cold drinks.’

Answer – (b) The Assertion and the Reason are correct but the Reason is not the
correct explanation of the Assertion.

3) Assertion: Carbon forms a large number of organic compounds.

Reason : Carbon atom contains 6 valence electrons.

Answer – (c) Assertion is true but the Reason is false.

4) Assertion: During the reaction esterification esters are produced.

Reason: Esters are sweet smelling compounds.

Answer – (b) The Assertion and the Reason are correct but the Reason is not the
correct explanation of the Assertion.

5) Assertion: Vegetable oils are unsaturated, react with hydrogen in presence of nickel to form vegetable ghee.

Reason: This reaction is saponification.

Answer – (c) Assertion is true but the Reason is false.

6) Assertion(A) : Carbon is the only element that can form large number of compounds.
Reason (R) : Carbon is tetravalent and shows the property of catenation.

Answer(d)

7) Assertion(A) : If the first member of a homologous series is methanal, its third member will be propanal.
Reason (R) : All the members of a homologous series show similar chemical properties.

Answer(b)

8) Assertion(A) : Diamond and graphite are allotropes of carbon.
Reason (R) : Some elements can have several different structural forms while in the same physical state. These forms are called allotropes.

Answer(a)

9) Assertion(A) : Soaps are not suitable for washing purpose when water is hard.
Reason (R) : Soaps have relatively weak cleansing action.

Answer(b)

10) Assertion(A) : Carbon compounds can form chain, branched and ring structures.
Reason (R) : Carbon exhibits the property of catenation.

Answer(a)

11) Assertion (A) : Carbon monoxide is extremely poisonous in nature.
Reason (R) : Carbon monoxide is formed by complete combustion of carbon.

Answer(c)

12) Q.7. Assertion (A) : Cooking oil decolourises bromine water.
Reason (R) : Cooking oil is a saturated compound.

Answer(b)

13) Assertion (A) : In a candle, wax vapours burn in sufficient supply of oxygen, which leads to blue flame.
Reason (R) : When the oxygen supply is sufficient, then fuels burn completely producing a blue flame.

Answer(a)

14) Assertion (A) : Alkanes give addition reaction.
Reason (R) : Addition reactions are a characteristic property of unsaturated hydrocarbons.

Answer(d)

15) Assertion(A): n-butane and iso-butane are examples of isomers.
Reason (R) : Isomerism is possible only with hydrocarbons having 4 or more carbon atoms.

Answer(b)

Direction: In the following questions, a statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as:
(a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
(b) Both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of
Assertion (A).
(c) Assertion (A) is true but Reason (R) is false.
(d) Assertion (A) is false but Reason (R) is true

1.Assertion: Bauxite is the most important ore of Aluminium.

     Reason: Carbon is used to reduce bauxite to aluminium

     Answer. (a)

  2.Assertion: Brass is an alloy of Zinc and Magnesium.

     Reason: Alloys are homogenous mixture of two or more metals.

     Answer. (d) 

     The statement of the Assertion is false but the Reason is true.

 3.Assertion: Iron can be obtained from Fe₂O₃ by reduction with aluminium.

     Reason: The process is known as thermite process.

      Answer . (a)

 both assertion and reason are right and it is the correct reason for assertion 

  4.Assertion: Elements Pt, Ag, noble gases, etc. occur in native state in nature.

      Reason: Elements which are attacked by moisture, oxygen and CO₂  of air occur in native state.

       Answer

Assertion is true for given statement while reason is wrong.

  5.Assertion: Reactivity Series is an arrangement of element based on their reactivity.

      Reason: Reactivity Series is used to separate elements based on their reactivity.

Answer. a) both assertion and reason are correct and reason is correct explanation of assertion

 6. Assertion :Metals like Na, K, Ca and Mg are never found in their free state     in nature
Reason :Metals are very reactive elements, so it combines with other non-metals to complete its octet. Metals like Na, K, Ca and Mg are never found in their state in nature.

Answer. (a) Both the Assertion and the Reason are correct and the Reason is the correct explanation of the Assertion.

7. Assertion: Nitrogen is a non-metal.
Reason: Nitrogen has 5 valence electrons.

Answer: b

The Assertion and the Reason are correct but the Reason is not the correct explanation of the Assertion.

8.Assertion: Al₂O₃, is an amphoteric oxide.
Reason: Al₂O₃ reacts with acid as well as base to form salt and water.

Answer: a
Both the Assertion and the Reason are correct and the Reason is the correct explanation of the Assertion.

 9.Assertion: Highly reactive metals are obtained by electrolytic reduction of their molten ore.
Reason: Highly reactive metals can be extracted by chemical reduction.

Answer: c
(c) Assertion is true but the Reason is false.

 10.Assertion: Copper does not reacts with the H₂SO₄.
Reason: Copper is more reactive than hydrogen

Answer: c

 Assertion is true but the Reason is false.

 11.Assertion: Silver becomes black in colour when exposed to atmosphere.
Reason: Silver reacts with H^S gas to form Ag,S which is black in colour.

Answer: a
Both the Assertion and the Reason are correct and the Reason is the correct explanation of the Assertion.

12. ASSERTION: Isotopes have same atomic masses.
    REASON: Isotopes have same atomic number and have similar chemical properties.

 Answer. (D)

 If assertion is INCORRECT, but reason is CORRECT


13. ASSERTION: Metallic character decreases across a period.
    REASON: Metals are electro-negative.

 Answer. (C)

 If assertion is CORRECT, but reason is INCORRECT



14. ASSERTION: Sodium bicarbonate is used in antacid medicines.
    REASON: It is a mild based which neutralizes the acidity of gastric juice.

Answer.(a)
If both assertion and reason are CORRECT and reason is the CORRECT explanation of the assertion.

 15.ASSERTION: Ethylene is an unsaturated hydrocarbon.
    REASON: Ethylene contains carbon-carbon triple covalent bond.

  Answer. (c )

   If assertion is CORRECT, but reason is INCORRECT

16. ASSERTION: Sodium and potassium is stored under kerosene.
    REASON: Sodium (Na) and Potassium (K) belongs to group IA, so they are alkali metals.

 Answer . (B)