Author Archives: Priyanka

In This Post we are  providing Chapter-9 Ray Optics and Optical Instrument NCERT MCQ for Class 12 Physics which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON RAY OPTICS AND OPTICAL INSTRUMENT

Question 1.
A short pulse of white light is incident from air to a glass slab at normal incidence. After travelling through the slab, the first color to emerge is
(a) blue.
(b) green.
(c) violet.
(d) red.

Answer: (d) red.

Question 2.
You are given four sources of light each one providing a light of a single color – red, blue, green and yellow. Suppose the angle of refraction for a beam of yellow light corresponding to a particular angle of incidence at the interface of two media is 90°. Which of the following statements is correct if the source of yellow light is replaced with that of other lights without changing the angle of incidence?
(a) The beam of red light would undergo total internal reflection.
(b) The beam of red light would bend towards normal while it gets refracted through the second medium.
(c) The beam of blue light would undergo total internal reflection.
(d) The beam of green light would bend away from the normal as it gets refracted through the second medium.

Answer: (c) The beam of blue light would undergo total internal reflection.

Question 3.
The optical density of turpentine is higher than that of water while its mass density is lower. Figure shows a layer of turpentine floating over water in a container. For which one of the four rays incident on turpentine in figure, the path shown is correct?

(a) 1.
(b) 2
(c) 3
(d) 4

Answer: (b) 2

Question 4.
There are certain material developed in laboratories which have a negative refractive index (figure). A ray incident from air (medium 1) into such a medium (medium 2) shall follow a path given by

Answer: (a)

Question 5.
Consider an extended object immersed in water contained in a plane trough. When seen from close to the edge of the trough the object will not look distorted because
(a) the apparent depth of the points close to the edge are nearer the surface of the water compared to the points away from the edge.
(b) the angle subtended by the image of the object at the eye is smaller than the actual angle subtended by the object in air.
(c) some of the points of the object far away from the edge may not be visible because of total internal reflection.
(d) water in a trough acts as a lens and magnifies the object.

Answer: (d) water in a trough acts as a lens and magnifies the object.

Question 6.
A rectangular block of glass ABCD has a refractive index 1.6. A pin is placed midway on the face AB (figure). When observed from the face AD, the pin shall

(a) appear to be near A.
(b) appear to be near D.
(c) appear to be at the center of AD.
(d) not be seen at all.

Answer: (d) not be seen at all.

Question 7.
An astronomical refractive telescope has an objective of focal length 20 m and an eyepiece of focal length 2 cm. Which one of the following is not possible?
(a) The length of the telescope tube is 20.02 m.
(b) The magnification is 1000.
(c) The image formed is inverted.
(d) An objective of a larger aperture will increase the brightness and reduce chromatic aberration of the image.

Answer: (d) An objective of a larger aperture will increase the brightness and reduce chromatic aberration of the image.

Question 8.
An object is placed at a distance of 40 cm from a concave mirror of focal length 15 cm. If the object is displaced through a distance of 20 cm towards the mirror, the displacement of the image will be:
(a) 30 cm away from the mirror
(b) 36 cm away from the mirror
(c) 30 cm towards the mirror
(d) 36 cm towards the mirror

Answer: (b) 36 cm away from the mirror

Question 9.
The refractive index of the material of a prism is √2 and the angle of the prism is 30°. One of the two refracting surfaces of the prism is made a mirror inwards, by silver coating. A beam of monochromatic light entering the prism from the other face will retrace its path (after reflection from the silvered surface) if its angle of incidence on the prism is:
(a) 60°
(b) 45°
(c) 30°
(d) zero

Answer: (b) 45°

Question 10.
A diverging lens with magnitude of focal length 25 cm is placed at a distance of 15 cm from a converging lens of magnitude of focal length 20 cm. A beam of parallel light falls on the diverging lens. The final image formed is:
(a) real and at a distance of 40 cm from the divergent lens
(b) real and at a distance of 6 cm from the convergent lens
(c) real and at a distance of 40 cm from convergent lens
(d) virtual and at a distance of 40 cm from convergent lens.

Answer: (c) real and at a distance of 40 cm from convergent lens

Question 11.
The bouncing back of light when it strikes a smooth or polished surface is called …………….. of light.

(a) Refraction
(b) Reflection
(c) Dispersion
(d) Divergence

Answer: (b) Reflection

Question 12.
When light is reflected from a polit, surface the angle of incidence is …………… to the angle of reflection.

(a) Equal
(b) Same
(c) Different
(d) zero

Answer: (a) Equal

Question 13.
The image formed by a plane mirror shows …………….. inversion.

(a) Incident
(b) Parallel
(c) Transverse
(d) Lateral

Answer: (d) Lateral

Question 14.
A plane drawn perpendicular to the principal axis and passing through the principal focus is called ………………. plane.

(a) Focal
(b) Principal focus
(c) Optical center
(d) Optical axis

Answer: (a) Focal

Question 15.
The size of the mirror is called its …………………..

(a) Axis
(b) Focal
(c) Principal axis
(d) Aperture

Answer: (d) Aperture

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In This Post we are  providing Chapter-8 Electromagnetic Waves NCERT MCQ for Class 12 Physics which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON ELECTROMAGNETIC WAVES

Question 1.
The dimensional formula of E⃗  is:
(a)[MLT^-2A^-1]
(b) [MLT^-3A^-1]
(c) [MLT^-2A^-2]
(d) None of these

Answer: (b) [MLT^-3A^-1]

Question 2.
The dimensional formula of is:
(a) [MLT^-2A^-1]
(b) [ML⁰T^-2A^-1]
(c) [ML⁰T^-3A^-1]
(d) None of these

Answer: (b) [ML⁰T^-2A^-1]

Question 3.
Which of the following has the dimensions of current?
(a) ε₀ E⃗ .dt→
(b) µ₀ E⃗ .dt→
(c) B⃗ .dl→µ0
(d) B⃗ .dl→ε0

Answer: (c) B⃗ .dl→µ0

Question 4.
Which of the following has the dimensions of charge?
(a) ε0E⃗ ds→
(b) µ₀ E⃗ .ds→
(c) ε0µ0 E⃗ .ds→
(d) µ0ε0 E⃗ .ds→

Answer: (a) ε0E⃗ ds→

Question 5.
Maxwell’s equation involving ddt B⃗  is obtained-from:
(a) Ampere’s law
(b) Gauss’s law
(c) Faraday’s law
(d) Biot-Savart’s law

Answer: (c) Faraday’s law

Question 6.
The dimensions of E⃗ , dl→ are identical to that of:
(a) potential
(b) charge
(c) current
(d) None of these

Answer: (a) potential

Question 7.
Which of the following laws was modified by Maxwell by introducing the displacement current?
(a) Gauss’s law
(b) Ampere’s law
(c) Biot-Savart’s law
(d).None of these

Answer: (b) Ampere’s law

Question 8.
Choose the wave relevant to telecommunication :
(a) ultraviolet
(b) infrared
(c) microwave
(d) visible light

Answer: (c) microwave

Question 9.
Electromagnetic waves have a speed of
(a) 3 × 10⁵ kms^-1
(b)3 × 10⁶ kms^-1
(c) 3 × 10⁷ kms^-1
(d) 3 × 10⁸ kms^-1

Answer: (a) 3 × 10⁵ kms^-1

Question 10.
Which of the following EMW has highest wavelength?
(a) X-ray
(b) ultraviolet rays
(c) infrared rays
(d) microwaves

Answer: (c) infrared rays

Question 11.
Displacement current is due to:
(a) the flow of electrons
(b) the Varying electric field
(c) the ionization of atmosphere
(d) the flow of protons

Answer: (b) the Varying electric field

Question 12.
Displacement current is always :
(a) equal to conduction current
(b) less than conduction current
(c) greater than conduction current
(d) the sum of current due to flow of positive and negative ions

Answer: (a) equal to conduction current

Question 13.
EMW are produced by:
(a) charge in uniform motion only
(b) charge at rest only
(c) accelerated or decelerated charge only
(d) all of the above

Answer: (c) accelerated or decelerated charge only

Question 14.
Who first demonstrated the existence of em waves?
(a) Hertz
(b) Maxwell
(c) Ampere
(d) Faraday

Answer: (a) Hertz

Question 15.
If B⃗  is the magnetic field vector and E⃗  is the electric field vector in an em wave, then which of the following relations is correct? Here c is the speed of fight:
(a) c = EB
(b) c = BE
(c) c = BE
(d) c = 1EB

Answer: (a) c = EB

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In This Post we are  providing Chapter-7 Alternating Current NCERT MCQ for Class 12 Physics which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON ALTERNATING CURRENT

1. Alternating voltage (V) is represented by the equation
(a) V(t) = V_m e^ωt
(b) V(t) = V_m sin ωt
(c) V(t) = V_m cot ωt
(d) V(t) = V_m tan ωt

Answer: b

2. The rms value of potential difference V shown in the figure is

Answer: c

3. The phase relationship between current and voltage in a pure resistive circuit is best represented by

Answer: b

4. In the case of an inductor
(a) voltage lags the current by π2
(b) voltage leads the current by π2
(c) voltage leads the current by π3
(d) voltage leads the current by π4

Answer: b

5. Which of the following graphs represents the correct variation of inductive reactance X_L with frequency u?

Answer: b

6. In a pure capacitive circuit if the frequency of ac source is doubled, then its capacitive reactance will be
(a) remains same
(b) doubled
(c) halved
(d) zero

Answer: c

7. Which of the following graphs represents the correct variation of capacitive reactance Xc with frequency v u?

Answer: c

8. In an alternating current circuit consisting of elements in series, the current increases on increasing the frequency of supply. Which of the following elements are likely to constitute the circuit?
(a) Only resistor
(b) Resistor and inductor
(c) Resistor and capacitor
(d) Only inductor

Answer: c

9. In which of the following circuits the maximum power dissipation is observed?
(a) Pure capacitive circuit
(b) Pure inductive circuit
(c) Pure resistive circuit
(d) None of these

Answer: c

10. In series LCR circuit, the phase angle between supply voltage and current is

Answer: a

11. In a series LCR circuit the voltage across an inductor, capacitor and resistor are 20 V, 20 V and 40 V respectively. The phase difference between the applied voltage and the current in the circuit is
(a) 30°
(b) 45°
(c) 60°
(d) 0°

Answer: d

12. At resonance frequency the impedance in series LCR circuit is
(a) maximum
(b) minimum
(c) zero
(d) infinity

Answer: b

13. At resonant frequency the current amplitude in series LCR circuit is
(a) maximum
(b) minimum
(c) zero
(d) infinity

Answer: a

14. Quality factor and power factor both have the dimensions of
(a) time
(b) frequency
(c) work
(d) angle

Answer: d

15. The natural frequency (ca0) of oscillations in LC circuit is given by

Answer: c

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In This Post we are  providing Chapter-6 Electromagnetic Induction NCERT MCQ for Class 12 Physics which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON ELECTROMAGNETIC INDUCTION

Question 1.
The coupling co-efficient of the perfectly coupled coils is:
(a) Zero
(b) 1
(c) slightly more than 1
(d) infinite

Answer: (b) 1

Question 2.
1 henry is equal to :
(a) weber/ampere
(b) weber/Volt
(c) weber ampere
(d) None of these

Answer: (a) weber/ampere

Question 3.
The magnetic field is parallel to a surface, then the magnetic flux through the surface is :
(a) zero
(b) small but not zero
(c) infinite
(d) large but not infinite

Answer: (b) small but not zero

Question 4.
In the expression e = –d∅dt, the -ve sign signifies:
(a) The induced e.m.f is produced only when magnetic flux decreases
(b) The induced e.m.f opposes the change in the magnetic flux
(c) The induced e.m.f is opposite to the direction of the flux
(d) None of these

Answer: (b) The induced e.m.f opposes the change in the magnetic flux

Question 5.
An e^– and a p^– are moving parallel to each other in a magnetic field. The magnetic force acting on the p⁺ is:
(a) 1840 times that on e^–
(b) less than that of e^–
(c) same as that of e^–
(d) slightly more than that of e^–

Answer: (c) same as that of e^–

Question 6.
Which of the following is not equal to a henry?
(a) Voltsecondampere
(b) Voltsecond2Coulomb
(c) Volt2secondCoulomb
(d) JolesecondCoulomb2Answer

Answer: (c) Volt2secondCoulomb

Question 7.
A transformer is used to light 100 W and 110 V lamp from a 220 V mains. If the main current is 0.5 A. Then the efficiency of the transformer is:
(a) 11%
(b) 50%
(c) 80%
(d) 90%

Answer: (d) 90%

Question 8.
The magnetic flux (∅) linked with a coil is related to the number of turns (N) of the coil as:
(a) f ∝ N
(b) f ∝ N^-1
(c) f ∝ N²
(d) f ∝ N^-2

Answer: (a) f ∝ N

Question 9.
The magnetic flux (∅) lined with a coil is related to its area (s) as:
(a) ∅ ∝ s
(b) ∅ ∝ s²
(c) ∅ ∝ s^1/2
(d) ∅ ∝ s^-1/2

Answer: (a) ∅ ∝ s

Question 10.
If the magnetic flux linked with a coil through which a current off ampere is set up is ∅, then the coefficient of self-inductance of the coil is:
(a) l∅
(b) ∅l
(c) ∅l
(d) None of these

Answer: (b) ∅l

Question 11.
In a uniform magnetic field B, a wire in the form of a semicircle of radius r rotated about the diameter of the circle with angular frequency ‘ω’. The axis of rotation is perpendicular to the field. If the total resistance of the circuit is R the mean power generated per period of rotation is :
(a) Bπr2ω2R
(b) (Bπr2ω)28R
(c) (Bπrω)22R
(d) (Bπrω2)28R

Answer: (b) (Bπr2ω)28R

Question 12.
The role of inductance is equivalent to:
(a) inertia
(b) force
(c) energy
(d) momentum

Answer: (a) inertia

Question 13.
A metal conductor of length 1 m rotates vertically about one of its ends at angular velocity 5 rad s^-1 . If the horizontal component of earth’s magnetism is 2 × 10^-5 T, then e.m.f. developed between the two ends of the conductor is:
(a) 5 µV
(b) 50 µV
(c) 5 mV
(d) 50 mV

Answer: (a) 5 µV

Question 14.
coil of L = 8.4 mH and R = 6 Ω is connected to a 12 V battery. The current in the coil is 1.0 A at approx. time of:
(a) 500 s
(b) 20 s
(c) 35 ms
(d) 1 ms

Answer: (d) 1 ms

Question 15.
If I current is flowing inductance L, then the dimension of 32 LI² is equivalent to:
(a) charge
(b) force
(c) momentum
(d) energy

Answer: (c) momentum

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In This Post we are  providing Chapter-5 Magnetism and Matter NCERT MCQ for Class 12 Physics which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON MAGNETISM AND MATTER

Question 1.
S.I. unit of flux is :
(a) Ohm
(b) Weber
(c) Tesla
(d) None

Answer: (b) Weber

Question 2.
What is the angle of dip at a place where the horizontal component of earth’s magnetic field is equal to the vertical component?
(a) 0°
(b) 30°
(c) 45°
(d) 90°

Answer: (c) 45°

Question 3.
Which of the following has a low value in ferrites?
(a) Conductivity
(b) Permeability
(c) Magnetic susceptibility
(d) All the above

Answer: (a) Conductivity

Question 4.
The dimensional representation of magnetic flux density is :
(a) [MLT^-2]
(b) [MLT^-2A^-1]
(c) [MLT^-2A^-2]
(d) [MT^-2A^-1]

Answer: (d) [MT^-2A^-1]

Question 5.
Tangent law is applicable only when:
(a) two uniform and mutually perpendicular magnetic fields exist
(b) two magnetic fields exist
(c) horizontal component of earth’s magnetic field is present
(d) uniform magnetic field are used

Answer: (a) two uniform and mutually perpendicular magnetic fields exist

Question 6.
Ferrites may be:
(a) ant. ferromagnetic
(b) ferromagnetic
(c) ferrimagnetic
(d) None of the above

Answer: (b) ferromagnetic

Question 7.
A magnetic bar of M magnetic moment is placed m the field of magnetic strength B, the torque acting on it is :
(a) M⃗ .B⃗ 
(b) –M⃗ .B⃗ 
(c) M⃗  × B⃗ .
(d) B⃗  × M⃗ 

Answer: (c) M⃗  × B⃗ .

Question 8.
The magnetic lines of force inside a bar magnet:
(a) do not exist
(b) depends on area of cross-section of bar magnet
(c) are from N-pole to S-pole of the magnet
(d) are from S-pole to N-pole of the magnet.

Answer: (d) are from S-pole to N-pole of the magnet.

Question 9.
A magnetic dipole moment is a vector quantity directed from:
(a) S to N
(b) N to S
(c) E to W
(d) W to E

Answer: (a) S to N

Question 10.
What is the magnetic field in the empty space enclosed by the toroidal solenoid of radius ‘R’? ,
(a) Infinity
(b) µ04π.2πlR
(c) µ04π.(πlR)
(d) zero

Answer: (d) zero

Question 11.
A current carrying power line carries current from west to east. What will be direction of magnetic field 1 meter above it?
(a) N to S
(b) S to N
(c) E to W
(d) W to E

Answer: (a) N to S

Question 12.
The dimensional representation of√ l/MB is similar to that of:
(a) frequency
(b) time
(c) distance
(d) speed

Answer: (b) time

Question 13.
On quadrupling the moment of inertia of a magnet, its frequency of oscillation will become:
(a) half
(b) double
(c) four times
(d) one-fourth

Answer: (a) half

Question 14.
The magnetic field strength due to a short bar magnet directed along its axial line at a distance r is B. What is its value at the same distance along the equatorial line?
(a) B
(b) 2B
(c) B2
(d) B4

Answer: (c) B2

Question 15.
The neutral point in the magnetic field of a horizontally placed bar magnet is a point where the magnetic field due to that bar magnet is:
(a) zero
(b) more than that of earth
(c) less than that of earth
(d) equal to that of earth

Answer: (d) equal to that of earth

In This Post we are  providing Chapter-4 Moving Charges and Magnetism NCERT MCQ for Class 12 Physics which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON MOVING CHARGES AND MAGNETISM

Question 1.
A charge moving with a velocity v in X-direction is subjected to a field of magnetic induction in the negative X direction. As a result, the charge will:
(a) remain undefeated
(b) retard along X-axis
(c) start moving in a circular path in YZ plane.
(d) move along a helical path around X-axis.

Answer: (a) remain undefeated

Question 2.
Two thin long parallel wires separated by a distance r are carrying a current I amp. each. The magnitude of the force per unit length applied by one wire on the other is:
(a) µ0I2r2
(b) µ0I22πr
(c) µ0I2πr
(d) µ0I24πr

Answer: (b) µ0I22πr

Question 3.
A wire is placed parallel to the lines of force in a magnetic field and a current flows in the wire, then:
(a) The wire will experience a force in the direction of the magnetic field.
(b) The wire will experience a force in a direction opposite to the magnetic field.
(c) It will experience a force in a direction perpendicular to the lines of force.
(d) Tire wire will not experience a force at all.

Answer: (d) Tire wire will not experience a force at all.

Question 4.
In order to increase the sensitivity of a moving coil galvanometer,
(a) the suspension wire should be made stiff.
(b) the arc of the coil should be reduced.
(c) the magnetic field should be increased.
(d) the number of turns in the coil should be reduced.

Answer: (a) the suspension wire should be made stiff.

Question 5.
Two particles A and B having equal charges after being accelerated through the same potential difference enter a region of uniform magnetic field and describe circular path of radii R₁ and R₂ respectively. The ratio of the masses of A to B is:
(a) (R1R2)^1/2
(b) (R2R1)
(c) (R1R2)²
(d) R1R2

Answer: (c) (R1R2)²

Question 6.
When a charged particle moves perpendicular to a uniform magnetic field, its:
(a) Energy and momentum both change.
(b) Energy and momentum both don’t change.
(c) Energy changes but momentum remains unchanged.
(d) Momentum changes but energy remains unchanged.

Answer: (d) Momentum changes but energy remains unchanged.

Question 7.
The force on a current carrying conductor in a magnetic field is maximum, when angle between the length of the conductor and the magnetic field is:
(a) π2
(b) π4
(c) π
(d) zero

Answer: (a) π2

Question 8.
What happens between the two streams of electrons moving parallel to each other in the same direction:
(a) attract each other
(b) cross the electric and magnetic field of each other.
(c) repel each other.
(d) none of these

Answer: (c) repel each other.

Question 9.
Magnetic field is not associated with:
(a) a charge in uniform motion.
(b) a decelerated charge.
(c) an accelerated charge.
(d) a stationary change.

Answer: (d) a stationary change.

Question 10.
A magnetic needle is kept in a non-uniform magnetic field. It experiences:
(a) a force and torque.
(b) a force but not a torque.
(c) a torque but not a force.
(d) neither a force nor a torque.

Answer: (a) a force and torque.

Question 11.
A proton and an electron enter a region in which a magnetic field is suddenly switched on. The forces experienced by them are:
(a) equal and opposite.
(b) different in magnitude but in same direction.
(c) in the ratio of 1840.
(d) same in magnitude and direction.

Answer: (a) equal and opposite.

Question 12.
Two protons move parallel to each other with equal speeds 3 × 10² m/s. The ratio of magnetic and electrical forces between them is:
(a) 10^-6
(b) 10^-3
(c) 10^-9
(d) 1

Answer: (a) 10^-6

Question 13.
A proton and an a particle enter in a uniform magnetic field with the same velocity. The period of rotation of the α-particle will be:
(a) four times that of the proton.
(b) three times that of the proton.
(c) two times that of the proton.
(d) same as that of the proton.

Answer: (c) two times that of the proton.

Question 14.
The magnetic field at the center of a square loop of side a carrying a current I is:
(a) µ04π √2 1a
µ04π 421√4π
(c) µ04π 8√2 1a
(d) none

Answer: (c) µ04π 8√2 1a

Question 15.
A circular of radius R carries a current I. The magnetic field at its centre is B. At what distance from the centre on the axis of the coil, the magnetic field will be B8?
(a) √2R
(b) √3R
(c) 2R
(d) 3R

Answer: (b) √3R

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In This Post we are  providing Chapter-3 Current Electricity NCERT MCQ for Class 12 Physics which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON CURRENT ELECTRICITY

Question 1.
The speed at which the current travels in a conductor is nearly:
(a) 3 × 10⁴ ms^-1
(b) 3 × 10⁶ ms^-1
(c) 3 × 10⁸ ms^-1
(d) 3 × 10¹⁰ ms^-1

Answer: (a) 3 × 10⁴ ms^-1

Question 2.
The resistance of a human body is about:
(a) 12 Ω
(b) 120 Ω
(c) 12 KΩ
(d) 120 MΩ

Answer: (c) 12 KΩ

Question 3.
The number of electrons that constitute 1 A of current is:
(a) 6.25 × 10¹⁶
(b) 6.25 × 10¹⁷
(c) 6.25 × 10¹⁸
(d) 6.25 × 10¹⁹

Answer: (c) 6.25 × 10¹⁸

Question 4.
How many different resistances are possible with two equal resistors?
(a) 2
(b) 3
(c) 4
(d) 5

Answer: (b) 3

Question 5.
Given three equal resistors, how many different combinations (taken all of them together) can be made?
(a) 3
(b) 4
(c) 5
(d) 6

Answer: (b) 4

Question 6.
Specific resistance of alkali metals is mostly affected by:
(a) temperature
(b) pressure
(c) magnetic field
(d) volume

Answer: (a) temperature

Question 7.
The example of a non-ohmic resistance is:
(a) copper wire
(b) filament lamp
(c) carbon resistor
(d) diode

Answer: (d) diode

Question 8.
If a certain piece of copper is to be shaped into a conductor of minimum resistance, its length (L) and cross-sectional area (a) shall respectively be :
(a) L, 2A
(b) L2, 2A
(c) 2L, 2A
(d) 2l, A2

Answer: (b) L2, 2A

Question 9.
The specific resistance of a rod of copper as compared to that of thin wire of copper is :
(a) less
(b) more
(c) same
(d) depends upon the length and area of cross-section of the wire

Answer: (c) same

Question 10.
A wire of resistance 3 Ω is cut into three pieces, which are then joined to form a triangle. The equivalent resistance between any corners of the triangle is :
(a) 23 Ω
(b) 32 Ω
(c) 12 Ω
(d) 13 Ω

Answer: (a) 23 Ω

Question 11.
The length of a conductor is halved. Its resistance will be :
(a) halved
(b) doubled
(c) unchanged
(d) quadrupled

Answer: (a) halved

Question 12.
In the above question, the conductance:
(a) halved
(b) doubled
(c) unchanged
(d) quadrupled

Answer: (b) doubled

Question 13.
Siemen is the unit of:
(a) resistance
(b) conductance
(c) specific conductance
(d) None of these

Answer: (b) conductance

Question 14.
How much electric energy is consumed by a 100 W lamp used for 6 hours everyday for 30 days?
(a) 18 kJ
(b) 18 kWh
(c) 1.8 J
(d) None of these

Answer: (b) 18 kWh

Question 15.
Suppose H₁ is the heat generated per second in the filament of a 100 W, 250 V lamp and H₂ is the heat generated in the filament of a 200 W, 250 V lamp. Then H₁/H₂ is equal to:
(a) 1
(b) 2
(c) 12
(d) 14

Answer: (c) 12

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In This Post we are  providing Chapter-1 Electrostatic Potential and Capacitance NCERT MCQ for Class 12 Physics which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON ELECTROSTATIC POTENTIAL AND CAPACITANCE

Question 1: A capacitor is charged by a battery. The battery is removed and another identical uncharged capacitor is connected in parallel. The total electrostatic energy of resulting system

(a) decreases by a factor of 2

(b) remains the same

(c) increases by a factor of 2

(d) increases by a factor of 4

Answer=A

Question 2: Choose the correct option

Assertion : Electric potential and electric potential energy  are different quantities.
Reason : For a system of positive test charge and point charge electric potential energy = electric potential.

(a) Assertion is correct, reason is correct; reason is a correct explanation for assertion.
(b) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(c) Assertion is correct, reason is incorrect
(d) Assertion is incorrect, reason is correct.

Answer=C

Question 3:  A long, hollow conducting cylinder is kept coaxially inside another long, hollow conducting cylinder of larger radius. Both the cylinders are initially electrically neutral

(a) A potential difference appears between the two cylinders when a charge density is given to the inner cylinder.

(b) A potential difference appears between two cylinders when a charge density is given to the outer cylinder.

(c) No potential difference appears between the two cylinders when a uniform line charge is kept along the axis of the cylinders.

(d) No potential difference appears between the two cylinders when same charge density is given to both the cylinders.

Answer=A

Question 4: The electrostatic force between the metal plates of an isolated parallel plate capacitor C having a charge Q and area A, is

(a) independent of the distance between the plates

(b) linearly proportional to the distance between the plates

(c) inversely proportional to the distance between theplates

(d) proportional to the square root of the distance betweenthe plates

Answer=A

Question 5:  Choose the correct option

Assertion : For a non-uniformly charged thin circular ring with net charge is zero, the electric field at any point on axis of the ring is zero.
Reason : For a non-uniformly charged thin circular ring with net charge zero, the electric potential at each point on axis of the ring is zero.

(a) Assertion is correct, reason is correct; reason is a correct explanation for assertion.

(b) Assertion is correct, reason is correct; reason is not a correct explanation for assertion

(c) Assertion is correct, reason is incorrect

(d) Assertion is incorrect, reason is correct.

Answer=D

Question 6: The electric potential inside a conducting sphere

(a) increases from center to surface
(b) decreases from center to surface
(c) remains constant from center to surface
(d) is zero at every point inside

Answer=C

Question 7:  It becomes possible to define potential at a point in an electric field because electric field

(a) is a conservative field
(b) is a non-conservative field
(c) is a vector field
(d) obeys principle of superposition

Answer=A

Question 8: Which of the following about potential at a point due to a given point charge is true ?

The potential at a point P due to a given point charge

(a) is a function of distance from the point charge.
(b) varies inversely as the square of distance from the point charge.
(c) is a vector quantity.
(d) is directly proportional to the square of distance from the point charge.

Answer=A

Question 9:  Which of the following quantities do not depend on the choice of zero potential or zero potential energy?

(a) Potential at a point
(b) Potential difference between two points
(c) Potential energy of a two-charge system
(d) None of these

Answer=B

Question 10: A cube of a metal is given a positive charge Question: For this system, which of the following statements is true?

(a) Electric potential at the surface of the cube is zero
(b) Electric potential within the cube is zero
(c) Electric field is normal to the surface of the cube
(d) Electric field varies within the cube

Answer=D

Question 11: The electric potential at a point on the equatorial line of an electric dipole is

(a) directly proportional to distance
(b) inversely proportional to distance
(c) inversely proportional to square of the distance
(d) None of these

Answer=D

Question 12: A hollow metal sphere of radius 5 cm is charged such that the potential on its surface is 10 V. The potential at a distance of 2 cm from the centre of the sphere is

(a) zero

(b) 10 V

(c) 4 V

(d) 10/3 V

Answer=B

Question 13: Choose the correct option

Assertion : Electric field is discontinuous across the surface of a spherical charged shell.
Reason : Electric potential is continuous across the surface of a spherical charged shell

(a) Assertion is correct, reason is correct; reason is a correct explanation for assertion.
(b) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(c) Assertion is correct, reason is incorrect
(d) Assertion is incorrect, reason is correct.

Answer=B

Question 14: From a point charge, there is a fixed point A. At A, there is an electric field of 500 V/m and potential difference of 3000 V. Distance between point charge and A will be

(a) 6 m

(b) 12 m

(c) 16 m

(d) 24 m

Answer=A

Question 15: Two metal pieces having a potential difference of 800 V are 0.02 m apart horizontally. A particle of mass 1.96 × 10^–15 kg is suspended in equilibrium between the plates. If e is the elementary charge, then charge on the particle is

(a) 8

(b) 6

(c) 0.1

(d) 3

Answer=D

In This Post we are  providing Chapter-1 Electric Charges and Fields NCERT MCQ for Class 12 Physics which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON ELECTRIC CHARGES AND FIELDS

Question 1.
Which one of the following is the unit of electric field?
(a) Coulomb
(b) Newton
(c) Volt
(d) N/C

Answer: (d) N/C

Question 2.
Three charges + 3q + q and Q are placed on a st. line with equal separation. In order to maket the net force on q to be zero, the value of Q will be :
(a) +3q
(b) +2q
(c) -3q
(d) -4q

Answer: (a) +3q

Question 3.
If an electric dipole is kept in a uniform electric field then resultant electric force on it is :
(a) always zero
(b) never zero
(c) depend upon capacity of dipole
(d) None

Answer: (a) always zero

Question 4.
The number of electron-taken out from a body to produce 1 coulomb of charge will be :
(a) 6.25 × 10¹⁸
(b) 625 × 10¹⁸
(c) 6.023 × 10²³
(d) None

Answer: (a) 6.25 × 10¹⁸

Question 5.
The work done in rotating an electric dipole in an electric field:
(a) W = ME (1 – cos θ)
(b) W = ME tan θ
(c)W = ME sec θ
(d) None

Answer: (a) W = ME (1 – cos θ)

Question 6.
If sphere of bad conductor is given charge then it is distributed on:
(a) surface
(b) inside the surface
(c) only inside the surface
(d) None

Answer: (d) None

Question 7.
Electric field in a cavity of metal:
(a) depends upon the surroundings
(b) depends upon the size of cavity
(c) is always zero
(d) is not necessarily zero

Answer: (d) is not necessarily zero

Question 8.
The dielectric constant of a metal is:
(a) 0
(b) 1
(c) ∞
(d) -1

Answer: (c) ∞

Question 9.
1 coulomb is equal to:
(a) 3 × 10⁹ e.s.u.
(b) 13 × 10⁹ e.s.u.
(c) 3 × 10¹⁰ e.s.u.
(d) 13 × 10¹⁰ e.s.u.

Answer: (a) 3 × 10⁹ e.s.u.

Question 10.
Each of the two point charges are doubled and their distance is halved. Force of interaction becomes p times, w here p is :
(a) 1
(b) 4
(c) 116
(d) 16

Answer: (d) 16

Question 11.
Coulomb’s law in vector form can be written as
F⃗  = (14πεn) (q1q2r2)r⃗ 
where ε₀ is the permittivity of free space. The SI units of ε₀ will be:
(a) N^-1m^-2C^-2
(b) Nm^-2C²
(c) N^-1m^-2C⁹.
(d) Nm^-2C²

Answer: (c) N^-1m^-2C⁹

Question 12.
The dimensional representation of cu will be :
(a) [MLT⁴ A²]
(b) [M^-1L^-3T⁴A²]
(c)[ML^-2T ]
(d) None of these

Answer: (b) [M^-1L^-3T⁴A²]

Question 13.
When placed in a uniform field, a dipole experiences:
(a) a net force
(b) a torque
(c) both a net force and torque
(d) neither a net force nor a torque

Answer: (b) a torque

Question 14.
A parrot comes and sits on a bare high power line. It will:
(a) experience a mild shock ‘
(b) experience a strong shock.
(c) get killed instantaneously
(d) not be affected practically

Answer: (d) not be affected practically

Question 15.
The SI units of electric dipole moment are:
(a) C
(b) Cm^-1
(c) Cm
(d) Nm^-1

Answer: (c) Cm

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In This Post we are  providing Chapter-13 Probability NCERT MCQ for Class 12 Math which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON PROBABILITY

Question 1.
The variance of random variable X i.e. σ2x or var (X) is equal to
(a) E(X²) + [E(X²)₂]²
(b) E(X) – [E(X²)]
(c) E(X²) – [E(X)]²
(d) None of these

Answer:(c) E(X²) – [E(X)]²

Question 2.
A coin is biased so that the head is 3 times likely to occur as a tail. If the coin is tossed twice, then find the probability distribution of the number of tails.

Answer:

Question 3.
A pair of the die is thrown 4 times. If getting a doubled is considered a success, then find the probability distribution of a number of successes.

Answer:

Question 4.
Find the probability of throwing utmost 2 sixes in 6 throws of a single die.
(a) 3518(56)3
(b) 3518(56)4
(c) 1829(23)4
(d) 1829(23)3

Answer:(b) 3518(56)4

Question 5.
A die is thrown again and again until three sixes are obtained. Find the probability of obtaining third six in the sixth throw of the die.
(a) 62523329
(b) 62125329
(c) 62523328
(d) 62023328

Answer:(c) 62523328

Question 6.
Ten eggs are drawn successively with replacement from a lot containing 10% defective eggs. Then, the probability that there is at least one defective egg is
(a) 1−7101010
(b) 1+7101010
(c) 1+9101010
(d) 1−9101010

Answer:(d) 1−9101010

Question 7.
The probability of a man hitting a target is 14. How many times must he fire so that the probability of his hitting the target at least once is greater than 23?
(a) 4
(b) 3
(c) 2
(d) 1

Answer:(a) 4

Question 8.
Eight coins are thrown simultaneously. Find the probability of getting at least 6 heads.
(a) 31128
(b) 37256
(c) 37128
(d) 31256

Answer:(b) 37256

Question 9.
A bag contains 6 red, 4 blue and 2 yellow balls. Three balls are drawn one by one with replacement. Find the probability of getting exactly one red ball.
(a) 14
(b) 38
(c) 34
(d) 12

Answer:(b) 38

Question 10.
Eight coins are thrown simultaneously. What is the probability of getting at least 3 heads?
(a) 37246
(b) 21256
(c) 219256
(d) 19246

Answer:(c) 219256

Question 11.
For the following probability distribution, the standard deviation of the random variable X is

(a) 0.5
(b) 0.6
(c) 0.61
(d) 0.7

Answer:(d) 0.7

Question 12.
A bag contains 5 red and 3 blue balls. If 3 balls are drawn at random without replacement the probability of getting exactly one red ball is
(a) 45196
(b) 135392
(c) 1556
(d) 1529

Answer:(c) 1556

Question 13.
A die is thrown and card is selected a random from a deck of 52 playing cards. The probability of gettingan even number on the die and a spade card is
(a) 12
(b) 14
(c) 18
(d) 34

Answer:(c) 18

Question 14.
A box contains 3 orange balls, 3 green balls and 2 blue balls. Three balls are drawn at random from the box without replacement. The probability of drawing 2 green balls and one blue ball is
(a) 328
(b) 221
(c) 128
(d) 167168

Answer:(a) 328

Question 15.
A flashlight has 8 batteries out of which 3 are dead. If two batteries are selected without replacement and tested, the probability that both are deal is
(a) 3356
(b) 964
(c) 114
(d) 328

Answer:(d) 328