set 10 MCQ Questions & Answers Detailed Explanation

Question : 1

Assertion (A):
A piece of copper and a piece of glass are heated to the same temperature. When touched, thereafter the copper piece appears hotter than the glass piece.
Reason (R):
The desity of copper is more than that of glass.
Code

a) Both (A) and (R) are true, but (R) is not the correct explanation of (A)

b) (A) is true, but (R) is false

c) Both (A) and (R) are true and (R) is the correct explanation of (A)

d) (A) is false, but (R) is true

Question : 2

The minimum distance of clear vision for a normal healthy eye of human being is supposed to be

a) 15 cm

b) 10 cm

c) 50 cm

d) 25 cm

Question : 3

Assertion (A):
With the increase of temperature, the viscosity of glycerin increases.
Reason (R):
Rise of temperature increases kinetic energy of molecules.
Code

a) Both (A) and (R) are true, but (R) is not the correct explanation of (A)

b) (A) is true, but (R) is false

c) Both (A) and (R) are true and (R) is the correct explanation of (A)

d) (A) is false, but (R) is true

Question : 4

A worker was working on the rail track. A boy at a distance holds his ear near the rail track. This boy was able to hear sound of the blow of workman twice. It is because of

a) The speed of sound is greater in air than in steel

b) Part of the sound wave is reflected between the rail tracks

c) The speed of sound is greater in steel than in air

d) His ears are at different distance from the source

Question : 5

Consider two identical iron spheres , one which lie on a thermally insulating plate, while the other hangs from an insulatory thread. Equal amount of heat is supplied to the two spheres

a) Their temperature will be equal

b) Temperature of A will be greater than B

c) Temperature of B will be greater than A

d) Can’t be predicted

Question : 6

Soap bubble looks coloured due to

a) interference

b) dispersion

c) reflection

d) Any one of these