The kinetic energy of an electron accelerated from rest through a potential difference of 3V will be:

Options

A. 3V
B. 3eV
C. 3erg
D. None of these

Explanation

To find the kinetic energy of an electron accelerated from rest through a potential difference of 3V, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the relationship between kinetic energy and electric potential:**
The kinetic energy (KE) gained by a charged particle (like an electron) when it is accelerated through a potential difference (V) is given by the equation:
\[ KE = qV \]
where \( q \) is the charge of the electron and \( V \) is the potential difference.

2. **Identify the charge of the electron:**
The charge of an electron (\( q \)) is approximately:
\[ q = 1.6 \times 10^{-19} \text{ coulombs} \]

3. **Substitute the values into the equation:**
Given that the potential difference \( V = 3 \text{ volts} \), we can substitute the values into the kinetic energy equation:
\[ KE = (1.6 \times 10^{-19} \text{ C})(3 \text{ V}) \]

4. **Calculate the kinetic energy:**
\[ KE = 4.8 \times 10^{-19} \text{ joules} \]

5. **Convert joules to electron volts (if necessary):**
Since 1 electron volt (eV) is defined as the energy gained by an electron when it is accelerated through a potential difference of 1 volt, we can express the kinetic energy in electron volts:
\[ KE = 3 \text{ eV} \]

### Final Answer:
The kinetic energy of the electron accelerated from rest through a potential difference of 3V is **3 eV**.

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