Question

If the drift velocity of electrons in a conductor is V, then the drift velocity in another conductor of same material, but double the cross section and carrying half the current of first conductor is.

• A. $V$
• B. $\frac{V}{4}$
• C. $\frac{V}{3}$
• D. $\frac{V}{6}$

Answer 1

The correct option is B $\frac{V}{4}$

$i=neA{v}_d;v_d\alpha \frac{i}{A}\frac{v_d^1}{v_d}=\frac{i^1}{i}\times \frac{A}{A^1}=\frac{i}{2i}\times \frac{A}{2A}{V}_d^1=\frac{V_d}{4}=\frac{V}{4}$