What is the reason for twinkling of stars ?
A. Dispersion of light
B. Total internal reflection
C. Atmospheric reflection
D. Atmospheric refraction
Answer: Option D
Solution(By Examveda Team)
Atmospheric refraction is the reason behind the twinkling of stars. The starlight on entering earth surface undergoes refraction continuously before it reaches to earth. The starlight bend towards the normal as it enters from rarer to denser medium. The air near the earth surface is denser than upper layers. Therefore the apparent position of the stars are slightly different from its actual position, when it is viewed from horizon. The apparent position of stars are not stationary and keeps on changing slightly, because the physical condition of the atmosphere are not stationary. Because of this the stars sometimes appears brighter and sometimes appear fainter.This Question Belongs to General Knowledge >> Physics
Which of the following terms is not used in the field of physics?
A. Latent heat
B. Nuclear fusion
C. Refractive index
D. Stock value
Radiocarbon is produced in the atmosphere as a result of
A. Collision between fast neutrons and nitrogen nuclei present in the atmosphere.
B. Action of ultraviolet light from the sun on atmospheric oxygen.
C. Action of solar radiations particularly cosmic rays on carbon dioxide present in the atmosphere.
D. Lightning discharge in atmosphere.
It is easier to roll a stone up a sloping road than to lift it vertical upwards because
A. Work done in rolling is more than in lifting.
B. Work done in lifting the stone is equal to rolling it.
C. Work done in both is same but the rate of doing work is less in rolling.
D. Work done in rolling a stone is less than in lifting it.
The absorption of ink by blotting paper involves:
A. Viscosity of ink
B. Capillary action phenomenon
C. Diffusion of ink through the blotting
D. Siphon action
Join The Discussion