Exercise 1

Question 11 :

Pa(Pascal) is the unit for

A). thrust
B). pressure
C). frequency
D). conductivity
Answer : Option B

Question 12 :

Planets do not twinkle because

A). they emit light of a constant intensity
B). their distance from the earth does not change with time
C). they are very far away from the earth resulting in decrease in intensity of light
D). they are nearer to earth and hence we receive a greater amount of light and, therefore minor variations in the intensity are not noticeable
Answer : Option D

Question 13 :

Metals are good conductors of electricity because

A). they contain free electrons
B). the atoms are lightly packed
C). they have high melting point
D). All of the above
Answer : Option A

Question 14 :

Let a thin capillary tube be replaced with another tube of insufficient length then, we find water

A). will overflow
B). will not rise
C). depressed
D). change its meniscus
Answer : Option B

Question 15 :

Out of the following pairs, choose the pair in which the physical quantities do not have identical dimension?

A). Pressure and Young's modules
B). Planck's constant and Angular momentum
C). Impulse and moment of force
D). Force and rate of change of linear momentum
Answer : Option C