light, heat, thermodynamics, wave motion, sound, optics & oscillations - Category wise Question and Answer Practice Test with Solutions

Question : 6 [UP UDA/LDA (Mains) 2010]

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 : 7 [PSC (Pre) 2019]

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 : 8 [IAS (Pre) 2000]

Assertion (A):
A stick is dipped in water in a slanting position. If observed sideways, the stick appears short and bent at the surface of the water.
Reason (R):
A light coming from the stick undergoes scattering from water molecules giving the stick a short and bent appearance.
Code

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 : 9

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 : 10 [UP (Pre) 2009]

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