Quiznetik

Physics | Set 13

1. The velocity of sound in moist air is more than in dry air because the moist air has

Correct : A. less density than city air

2. The owl can see most clearly in total darkness because –

Correct : B. it has large eyes with orbs directed forward, giving it binocular sight

3. Water boils at a lower temperature on the hills because –

Correct : C. there is a decrease in air pressure on the hills

4. Bats can sense obstacles because they produce –

Correct : B. ultrasonic sound waves

5. A satellite in vacuum -

Correct : D. does not require any energy for orbiting

6. The sky appears blue because –

Correct : C. The atmosphere scatters blue colour more than the others

7. Mercury is commonly used as a thermometric fluid rather than water because

Correct : C. mercury has greater visibility than water

8. A barometer is kept inside a bell jar. Air is slowly pumped out of the jar.

Correct : A. The mercury level starts rising

9. Melting point of ice               .

Correct : B. decreases with increase of pressure

10. The threshold frequency is the frequency below which –

Correct : C. photo electric emission is not possible

11. The blue colour of sky is due to –

Correct : C. scattering of shorter wave-lengths of sunlight in the atmosphere

12. Metal tea pots have wooden handles because –

Correct : B. it prevents electric shock

13. Flywheel is an important part of a steam engine because it –

Correct : B. helps the engine in keeping the speed uniform

14. The rice is cooked more quickly in a pressure cooker because –

Correct : D. water boils at a higher temperature under pressure.

15. Photophobia is -

Correct : C. the adjustment of the eye for light

16. Where do the electrical charges reside in a charged conductor?

Correct : D. outer surface of the body