• By SUBHASH
• 16 Sep 2021

1. How many periods and groups are present in the periodic table? a) 7 periods and 18 groups b) 8 periods and 7 groups c) 7 periods and 7 groups d) 8 periods and 8 groups Answer: (a) 7 periods and

• By SUBHASH
• 16 Sep 2021

1. Which of the following structures correctly represents the electron dot structure of a chlorine molecule? Answer: (a) Explanation: In an electron dot structure of a molecule there must be shown eight electrons (in the form of dots or crosses) around each element

• By SUBHASH
• 16 Sep 2021

1. The non-metal which is liquid at room temperature is: a) Mercury b) Bromine c) Carbon d) Helium Answer: (b) Bromine Explanation: Bomine is the only non-metal which exists as a liquid at room temperature. 2. The number of protons in an atom of

• By SUBHASH
• 16 Sep 2021

1.Sodium carbonate is a basic salt because it is a salt of(a) weak acid and weak base(b) strong acid and weak base(c) weak acid and strong base Answer: (c) weak acid and strong base.Explation= Sodium carbonate is a basic salt

• By SUBHASH
• 16 Sep 2021

1.In which mode of nutrition an organism de-rives its food from the body of another living organism without killing it?(a) Saprotrophic nutrition(b) Parasitic nutrition(c) Holozoic nutrition(d) Autotrophic nutrition Answer: b 2. The mode of nutrition found in fungi is:(a) Parasitic nutrition(b)

• By SUBHASH
• 16 Sep 2021

1. For some integer m, every odd integer is of the form (A) m                                       (B) m + 1 (C) 2m                                     (D) 2m + 1 Answer:  D Explanation: As the number 2m will always be even, so if we add

• By SUBHASH
• 16 Sep 2021

Question 1.In the given figure, AD = BC and BD = AC, prove that ∠DAB = ∠CBA.Solution:In ∆DAB and ∆CBA, we haveAD = BC [given]BD = AC [given]AB = AB [common]∴ ∆DAB ≅ ∆CBA [by SSS congruence axiom]Thus, ∠DAB =∠CBA

• By SUBHASH
• 16 Sep 2021

Question 1.Define :(a) a square (b) perpendicular lines.Solution:(a) A square : A square is a rectangle having same length and breadth. Here, undefined terms are length, breadth and rectangle.(b) Perpendicular lines : Two coplanar (in a plane) lines are perpendicular,

• By SUBHASH
• 16 Sep 2021

Question 1.Represent √3 on the number line.Solution:On the number line, take OA = 1 unit. Draw AB = 1 unit perpendicular to OA. Join OB.Again, on OB, draw BC = 1 unit perpendicular to OB. Join OC.By Pythagoras Theorem, we

• By SUBHASH
• 16 Sep 2021

Question 1.In the given figure, AB || CD, ∠FAE = 90°, ∠AFE = 40°, find ∠ECD.Solution:In AFAE,ext. ∠FEB = ∠A + F= 90° + 40° = 130°Since AB || CD∴ ∠ECD = FEB = 130°Hence, ∠ECD = 130°. Question 2.In