Physics
Stars twinkle because

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

ANSWER DOWNLOAD EXAMIANS APP

Physics
Which one of the following is not a property of electromagnetic waves?

Oscillating electric field and magnetic field are perpendicular to each other.
Electromagnetic waves do not require a medium to propagate.
Electromagnetic waves do not show interference and diffraction.
Electromagnetic waves are transverse waves

ANSWER DOWNLOAD EXAMIANS APP