Question

The drift velocity of the electrons is given by, where \(n\) is number of electrons per unit volume, \(I\) is the current, \(e\) is charge on electron and \(A\) is area:

• A. \(v_d=\dfrac{I}{nAe}\)
• B. \(v_d=\dfrac{ne}{IA}\)
• C. \(v_d=\dfrac{Ie}{nA}\)
• D. \(v_d=\dfrac{neA}{I}\)

Hint:

For drift velocity, remember \(I=nAe v_d\), so \(v_d=\frac{I}{nAe}\).

Answer 1

The Correct Option is A

Concept:
Electric current in a conductor due to drifting electrons is given by: \[ I=nAe v_d \] where, \[ n=\text{number of electrons per unit volume} \] \[ A=\text{area of cross-section} \] \[ e=\text{charge of electron} \] \[ v_d=\text{drift velocity} \]

Step 1: Start with current formula. \[ I=nAe v_d \]

Step 2: Rearrange for drift velocity. \[ v_d=\frac{I}{nAe} \]

Step 3: Final answer. \[ \therefore \text{Correct Answer is (A)} \]