Question

Without external load, the p-n junction solar cell, when kept in the sun, is reverse biased
True
False

Answer 1

"Without external load, the p-n junction solar cell, when kept in the sun, is reverse biased" is a true statement .

Explanation:

A solar cell is also called as Photo cell  which converts light energy into electrical energy.

It is PN junction .

When light is not incident on solar cell, then there is a balance between drift and diffusion and number of electrons and holes are equal between two regions and net current flow is zero.
So , A reverse bias is applied in order to increase the effect of an internal electric field in the junction thus causing the imbalance of drift and diffusion across depletion region.

"In Dark, The solar cell acts as Diode in Forward bias"

Answer 2

This statement is quite true as a solar cell is the most important thing in the formation of a P-N junction. 

When the p and n materials form a joint, excess electrons from n type material are travelled to the p side and the excess holes from the p side are sent to the n side. Thus, positive ions are formed at the p side and negative ions at the n side resulting in a voltage from the electric field formed at the junction.