Physics
Stars twinkle because

the refractive index of the different layers of the earth's atmosphere ch
None of these
the intensity of light emitted by them changes with time.
the distance of the stars from the earth changes with time.

ANSWER DOWNLOAD EXAMIANS APP

Physics
Superconductors are substances which

offer no resistance to the flow of electricity
conduct electricity at low temperature
offer high resistance to the flow of current
conduct electricity at high temperatures

ANSWER DOWNLOAD EXAMIANS APP