Physics
In radio-communication, the signals emitted by transmitting antenna are reflected on

Ionosphere
Troposphere
Ozonosphere
Stratosphere

ANSWER DOWNLOAD EXAMIANS APP

Physics
Planets do not twinkle because

Their distance from the earth does not change with time
They are nearer to earth and hence we receive a greater amount of light.
They are very far away from the earth resulting in decrease in intensity of light
They emit light of a constant intensity

ANSWER DOWNLOAD EXAMIANS APP