What happens to the drift velocity `(v_(d))` of electrons and to the resistance (R), if the length of a conductor is doubled (keeping potential difference unchanged)?

Explanation

To solve the problem, we need to analyze the effects of doubling the length of a conductor on the drift velocity of electrons and the resistance of the conductor while keeping the potential difference constant.

### Step-by-Step Solution:

1. **Understanding Drift Velocity**:
The drift velocity \( v_d \) of electrons in a conductor is given by the formula:
\[
v_d = \frac{eE\tau}{m}
...