Question

In a photoelectric cell current found zero for negative potential 1V, 2V, 3V then stopping potential is
A. $3\text{ }V$
B. $2\text{ }V$
C. $\le 1\text{ }V$
D. $\langle 1$

Answer 1

Hint: At first, the students know and describe what is a photoelectric cell and how it can be used. Then they must understand and write the concept of the stopping potential and then they have to make a graph of the photocurrent versus the stopping potential and then decide the answer. This will help you in answering this question.

Complete step by step answer:
First of all we must know what a photoelectric cell is, so a photo electric cell is a photovoltaic or a photocell which is actually an electronic device which usually converts solar or light energy to electric power, by the principle of photoelectric effect.
At first we need to know what is stopping potential, so according to the question stopping potential is nothing but the minimum negative potential given to a photocell for which the photoelectric current becomes zero.
Now, let us draw the graph for the photocurrent versus the stopping potential. Here we can see that the stopping potential when a current in a photoelectric cell becomes zero for the negative potential $1\text{ }V,2\text{ }V,3\text{ }V$ is always less than one.
So, we can say that $\langle 1$ is the correct answer. This has been given as option D.

Note: Students must have a clear concept of what is stopping potential and why it will be important. They must also know what a photoelectric cell is and why it is called a photoelectric cell, they must know how to draw or represent the graph of stopping potential versus the photocurrent.