Question

An electron is accelerated through a potential difference of 5 volts. The energy gained by the electron will be:

• A. 5 joule
• B. 5 eV
• C. 5 erg
• D. 5 watt

Hint:

1 electron-volt (eV) is the energy gained by an electron when accelerated through 1 volt: \[ 1 \, \text{eV} = 1.6 \times 10^{-19} \, \text{Joules} \]

Answer 1

The Correct Option is B

When a charge \( q \) is accelerated through a potential difference \( V \), the energy gained by the charge is given by the relation: \[ E = qV \] For an electron, the charge is: \[ q = 1 \, \text{e} = 1.6 \times 10^{-19} \, \text{C} \] Given the potential difference: \[ V = 5 \, \text{V} \] Substituting the values into the energy formula: \[ E = 1e \times 5V = 5 \, \text{eV} \] So, the energy gained by the electron is \( 5 \) electron volts (eV), which is equivalent to the energy an electron acquires when accelerated through a potential difference of 5 volts.