set 5 MCQ Questions & Answers Detailed Explanation

Question : 1

An underwater explosion is caused near the sea-shore. There are two observers, X under water and Y on land, each at a distance of 1 km from the point of explosion then

a) Both will hear the sound at the same time

b) X will hear the sound earlier

c) Y will hear the sound earlier

d) Y will not hear the sound at all

Question : 2

Assertion (A):
A piece of ice added to the drink, cools it.
Reason (R):
Ice takes latent heat from the drink for melting resulting in the cooling of the drink.
Select the correct answer using the codes given below.

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 : 3

Cloudy nights are warmer compared to clear cloudless nights, because clouds:

a) reflect back the heat given off by earth

b) prevent clod waves from the sky from descending on earth

c) produce heat and radiate it towards earth

d) absorb heat from the atmosphere and send it towards earth

Question : 4

The technique used to transmit audio signals in television broadcast is

a) Pulse code modulation

b) Frequency modulation

c) Amplitude modulation

d) Time dimension multiplication

Question : 5

Which one of the following is used as an antifreeze for the automobile engines?

a) Ethylene glycol

b) Methanol

c) Ethanol

d) Propyl alcohol

Question : 6

Assertion and Reason are given below.
Assertion (A):
We prefer the white dress in winters.
Reason (R):
White dresses are good reflectors of heat.
Which one among these is the right answer.

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