Question

The drift velocity of electrons in a linear conductor of given length under a potential can be doubled by

• A. decreasing the potential 4 times
• B. increasing the potential 2 times
• C. decreasing the potential 8 times
• D. increasing the potential 4 times
• E. decreasing the potential 2 times

Hint:

$v_d$ is also proportional to current ($I = nAev_d$).

Answer 1

The Correct Option is B

Step 1: Concept
Drift velocity $v_d = \frac{eV\tau}{mL}$, so $v_d \propto V$.

Step 2: Meaning
Drift velocity is directly proportional to the applied potential difference.

Step 3: Analysis
To double the velocity, the potential must also be doubled.

Step 4: Conclusion
Increase the potential 2 times.
Final Answer: (B)