Question

A potential difference of $6\text{V}$ is applied across a conductor of length $0.12\text{m}$. The drift velocity of an electron is
$[$mobility of electron$=5.6\times {10}^{-6}{\text{m}}^2\text{/Vs}]$

• A. $1.4\times {10}^{-4}\text{m/s}$
• B. $2.8\times {10}^{-6}\text{m/s}$
• C. $5.6\times {10}^{-4}\text{m/s}$
• D. $2.8\times {10}^{-4}\text{m/s}$

Answer 1

The correct option is D $2.8\times {10}^{-4}\text{m/s}$

Given:
$\mu =5.6\times {10}^{-6}{\text{m}}^2\text{/Vs};$
$V=6\text{V};l=0.12\text{m}$

From definition of mobility,

$\mu =\frac{v_d}{E}$

$\Rightarrow \mu =\frac{v_{d}l}{V}(\because E=V/l)$

putting the value

$\Rightarrow 5.6\times {10}^{-6}=\frac{v_d\times 0.12}{6}$

$\therefore v_d=2.8\times {10}^{-4}\text{m/s}$

Hence, option $\left(d\right)$ is correct.