Nights are cooler in the deserts because:
- (A) The sky is generally cloudy
- (B) Sand radiates heat less quickly as compared to earth
- (C) The sky is generally clear
- (D) Sand radiates heat more quickly as compared to earth
- (D) Sand radiates heat more quickly as compared to earth
The wet camel hair, when brushed, cling together due to:
- (A) Virosis
- (B) Elasticity
- (C) Adhesion
- (D) Surface tension
- (C) Adhesion
Pressure cooker is fast in cooking rice because:
- (A) It lets the steam escape
- (B) High pressure raises the boiling point of water
- (C) High pressure crushes the hard covering of rice grains
- (D) High pressure makes the rice cooked
- (B) High pressure raises the boiling point of water
Which of the following is NOT caused by atmospheric refraction of light?
- (A) Sun appearing red at sunset
- (B) Twinkling of stars at night
- (C) Sun appearing higher in the sky than it actually is
- (D) Sun becoming visible two or three minutes before actual sunrise
- (C) Sun appearing higher in the sky than it actually is
Oil rises up the wick in a lamp because:
- (A) Oil is volatile
- (B) Of the capillary action phenomenon
- (C) Oil is very light
- (D) Of the diffusion of oil through the wick
- (B) Of the capillary action phenomenon
Tiredness is felt on the top of the mountains because of:
- (A) Low temperature
- (B) High temperature
- (C) Low pressure outside the body
- (D) High pressure outside the body
- (C) Low pressure outside the body
Clothes keep us warm in winter because:
- (A) They supply heat
- (B) They do not radiate heat
- (C) They prevent the heat of the body from escaping
- (D) They absorb heat quickly
- (C) They prevent the heat of the body from escaping
Rainbow is produced by tiny rain drops suspended in front of sun rays as a result of:
- (A) Reflection and interference
- (B) Interference and refraction
- (C) Refraction and dispersion
- (D) Reflection, refraction and dispersion
- (D) Reflection, refraction and dispersion
Why is it easier to swim in a sea than a river?
- (A) Seawater is still while river water in running
- (B) Salinity of seawater is more than that of river water
- (C) Density of seawater is more than that of river water
- (D) Density of seawater is less than that of river water
- (C) Density of seawater is more than that of river water
An ice cube is floating in a glass of water. How will the water level in the glass be affected when the ice cube melts?
- (A) It will remain unchanged
- (B) It will rise
- (C) It will go down
- (D) It would first go up but later on it will go down
- (A) It will remain unchanged