At room temperature, copper has free electron density of 8.4 × 1028m-3. The electron drift velocity in a copper conductor of cross-sectional area of 10-6m2 and carrying a current of 5.4 A, will be

Question

At room temperature, copper has free electron density of 8.4 × 1028m-3. The electron drift velocity in a copper conductor of cross-sectional area of 10-6m2 and carrying a current of 5.4 A, will be (A) 4ms-1 (B) 0.4ms-1 (C) 4cms-1 (D) 0.4mms-1

Tardigrade Admin · Accepted Answer

Drift velocity in a copper conductor Vd= (i/neA)= (5.4/8.4 × 1028× 1.6 × 10-19× 10-6) =0.4 × 10-3ms-1 0.4mms-1

Q. At room temperature, copper has free electron density of $8.4 \times 10^{28} m^{- 3}$ .
The electron drift velocity in a copper conductor of cross-sectional area of $10^{- 6} m^{2}$ and carrying a current of 5.4 A, will be

$4 m s^{- 1}$

$0.4 m s^{- 1}$

$4 c m s^{- 1}$

$0.4 mm s^{- 1}$

Drift velocity in a copper conductor
$V_{d} = \frac{i}{n e A}$ = $\frac{5.4}{8.4 \times 10 ^{28} \times 1.6 \times 10 ^{- 19} \times 10 ^{- 6}}$
$= 0.4 \times 10^{- 3} m s^{- 1}$
$0.4 mm s^{- 1}$

Q. At room temperature, copper has free electron density of 8.4×1028m−3. The electron drift velocity in a copper conductor of cross-sectional area of 10−6m2 and carrying a current of 5.4 A, will be

4ms−1

0.4ms−1

4cms−1

0.4mms−1