Question

which element used in the filament of photoelectric cell that convert light energy into electric energy

Answer 1

(c) Rubidium

Explanation :- Rubidium is silver - white , chemical element. It is used in photoelectric shells because it is highly electropositive element . When rays of light strikes it surface it ejects number of electrons .
So, Rubidium is the correct answer . Rubidium is used in the filament of photoelectric shells that convert light energy into electric energy

Answer 2

Photoelectric cell: A device using a photoelectric effect to generate current using light is called as a photoelectric cell.

Photo emission takes place and the current flows in the circuit.

Rubidium is the  element used in the filament of photoelectric cell that convert light energy into electric energy.

Reason:

• High ohmic resistance.
• Less current leak.

Hence, (c) Rubidium is the answer.