set 14 MCQ Questions & Answers Detailed Explanation

Question : 1

The regions of compressions and rarefractions of sound wave are·establisbed because

a) the reflected sound wave at fixed end interferes with the incident wave

b) the sound wave undergoes diffraction behind obstacles

c) the longitudinal movement of air molecules produce pressure fluctuations

d) the speed of the sound wave changes as it travels through a medium

Question : 2

Wireless communication is reflected back to the Earth’s surface by the

a) Ionosphere

b) Stratosphere

c) Troposphere

d) Exosphere

Question : 3

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 – 4, B – 3, C – 1, D – 2

Question : 4

Consider the following statements:

1. Steam at 100°C and boiling water at 100°C contain same amount of heat.
2. Latent heat of fusion of ice is equal to the latent heat of vaporization of water.
3. In an air-conditioner, heat is extracted from the room air at the evaporator coils and is rejected out at the condenser coils.

a) 2 and 3

b) 1 and 2

c) Only 2

d) Only 3

Question : 5

Consider the following phenomena.

1. Size of the Sun at dusk
2. Colour of the Sun at dawn
3. Moon being visible at dawn
4. Twinkle of stars in the sky
5. Polestar being visible in the sky

a) 1, 2 and 4

b) 3, 4 and 5

c) 1, 2 and 3

d) 2, 3 and 5

Question : 6

Water has maximum density at

a) –4°C

b) 0°C

c) 32°F

d) 4°C