21)

______ are also known as heat waves.

SSC CPO 2020

A)

X-rays

B)

Gamma rays

C)

Light waves

D)

Infra-red waves

22)

In a galvanic cell, the half-cell in which oxidation takes place is called ______ and it has a negative potential with respect to the solution.

SSC CPO 2020

A)

anode

B)

diode

C)

triode

D)

cathode

23)

The phenomenon of deviation of light rays from their original path, when they pass from one medium to another, is called ______.

SSC CPO 2020

A)

diffraction

B)

obstruction

C)

refraction

D)

reflection