Elements Of Remote Sensing
Critical angle of electromagnetic radiation takes place if

Angle of incidence is equal to angle of refraction
Angle of refraction is equal to 90°
Angle of incidence is equal to 90°
Angle of incidence is greater than the angle of refraction

ANSWER DOWNLOAD EXAMIANS APP

Elements Of Remote Sensing
Geodimeter is based on:

High frequency radio waves
The visible light as carrier with frequency of the order of 5 × 1014 Hz
Propagation of infrared radiation
Propagation of modulated light waves

ANSWER DOWNLOAD EXAMIANS APP