An electron of charge 'e' coulomb passes through a potential difference of `V` volts. Its energy in 'joules' will be

Options

A. `V//e`
B. `eV`
C. `e//V`
D. `V`

Explanation

To find the energy of an electron passing through a potential difference of \( V \) volts, we can use the relationship between electric potential energy and charge. Here’s a step-by-step solution:

### Step-by-Step Solution:

1. **Understand the Concept**: When a charged particle, such as an electron, moves through a potential difference, it gains kinetic energy. The amount of energy gained is directly related to the charge of the particle and the potential difference it moves through.

2. **Identify the Charge of the Electron**: The charge of an electron is denoted as \( e \). In SI units, this charge is approximately \( 1.6 \times 10^{-19} \) coulombs.

3. **Use the Formula for Kinetic Energy**: The kinetic energy (KE) gained by the electron when it passes through a potential difference \( V \) is given by the formula:
\[ KE = Q \cdot V \]
where \( Q \) is the charge of the electron and \( V \) is the potential difference.

4. **Substitute the Charge of the Electron**: Since the charge \( Q \) of the electron is \( e \), we can substitute this into the formula:
\[ KE = e \cdot V \]

5. **Express the Energy in Joules**: The energy gained by the electron as it passes through the potential difference \( V \) is therefore:
\[ \text{Energy} = e \cdot V \text{ joules} \]

### Final Answer:
The energy of the electron in joules is given by:
\[ \text{Energy} = e \cdot V \text{ joules} \]