set 4 MCQ Questions & Answers Detailed Explanation

Question : 1

Match list I with list II and select the correct answer using the codes given below the lists.

a) A – 3, B – 4, C – 2, D – 1

b) A – 2, B – 3, C – 4, D – 1

c) A – 2, B – 1, C – 4, D – 3

d) A – 3, B – 4, C – 1, D – 2

Question : 2

Why is sound heard with more intensity through CO₂ than through the air ?

a) Density of CO₂ is less than that of air

b) Density of CO₂ is more than that of air

c) Air is bad conductor of heat

d) CO₂ is a compound, but air is a mixture of gases.

Question : 3

Decibel unit is used to measure

a) Sound intensity

b) Magnitude of earthquake

c) Light intensity

d) None of the above

Question : 4

The colour of an opaque object is due to the colour it

a) Reflects

b) Refracts

c) Absorbs

d) Scatters

Question : 5

Assertion (A):
The danger signal is made up of red colour.
Reason (R):
Red colour is scattered the least.
Select the correct answer using the codes given below.

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

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

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

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

Question : 6

Consider the following statements : Sound waves can undergo

1. reflection
2. refraction
3. interference

a) 2 and 3 only

b) 1 and 2 only

c) 1 and 3 only

d) 1, 2 and 3