Physics
Rainbow is due to

diffusion of sunlight through water droplets
refraction and reflection of sunlight by water droplets
absorption of sunlight in minute water droplets
ionisation of water deposits

ANSWER DOWNLOAD EXAMIANS APP

Physics
RADAR is used for:

locating submerged submarines.
detecting and locating the position of objects such as Aeroplanes.
locating geostationary satellites.
receiving a signals in a radio receiver.

ANSWER DOWNLOAD EXAMIANS APP

Physics
What is refractive index ?

It is defined as the ratio of speed of light in vacuum to the speed of light in the medium.
It is defined as the product of speed of light in medium and in vacuum.
None of above
It is defined as the ratio of speed of light in the medium to the speed of light in vacuum.

ANSWER DOWNLOAD EXAMIANS APP