Physics
A solid needle placed horizontally on the surface of the water floats due to

Capillary action
Viscosity of water
Water pressure
Surface tension of water

ANSWER DOWNLOAD EXAMIANS APP

Physics
Rainbow is due to

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

ANSWER DOWNLOAD EXAMIANS APP