Question

A charged particle is moving in an electric field of 6 x 10-10 Vm-1 with mobility 5×106 m2/Vs, its drift velocity is

• A. 2.5×10-4 m/s
• B. 1.2×10-4 m/s
• C. 3×10-3 m/s
• D. 8.33×10-3 m/s

Answer 1

Answer: (C)

3 × 10-3 m/s

Answer 2

The drift velocity ($v_d$) of a charged particle in an electric field ($E$) is related to its mobility ($\mu$) by the formula:

$v_d = \mu E$

Given:

Electric field, $E = 6 \times 10^{-10} \, \text{V} \, \text{m}^{-1}$

Mobility, $\mu = 5 \times 10^6 \, \text{m}^2/\text{V}/\text{s}$

Substitute the given values into the formula:

$v_d = (5 \times 10^6 \, \text{m}^2/\text{V}/\text{s}) \times (6 \times 10^{-10} \, \text{V} \, \text{m}^{-1})$

$v_d = (5 \times 6) \times (10^6 \times 10^{-10}) \, \text{m/s}$

$v_d = 30 \times 10^{(6 - 10)} \, \text{m/s}$

$v_d = 30 \times 10^{-4} \, \text{m/s}$

To express this in standard scientific notation:

$v_d = 3.0 \times 10^1 \times 10^{-4} \, \text{m/s}$

$v_d = 3.0 \times 10^{(1 - 4)} \, \text{m/s}$

$v_d = 3 \times 10^{-3} \, \text{m/s}$