# The metal mainly used in devising photoelectric cells is :

Question:

The metal mainly used in devising photoelectric cells is :

(1) $\mathrm{Na}$

(2) Li

(3) $\mathrm{Rb}$

(4) $\mathrm{Cs}$

1. Na

2. Li

3. Rb

4. Cs

Correct Option: , 4

Solution:

Cesium has lowest ionisation enthalpy and hence it shows photoelectric effect to the maximum extent. So, it is used in photo electric cell.