Question

The speed at which electric current travels in a conductor is nearly

• A. $3\times {10}^{4}m{s}^{-1}$
• B. $3\times {10}^{5}m{s}^{-1}$
• C. $3\times {10}^{6}m{s}^{-1}$
• D. $3\times {10}^{8}m{s}^{-1}$

Answer 1

Answer: (D)

$3\times {10}^{8}m{s}^{-1}$

In a conductor , the speed of electric field is almost equal to $c=3\times {10}^{8}m/s$.

Hence, this is the speed with which electric current travels in a conductor.

Though the drift speed is of the order of ${10}^{-3}m/s$ and the speed of electrons is of the order of ${10}^{6}m/s$.

The current starts flowing as soon as the electron starts drifting and hence the speed of current is same as that of electric field that is nearly $3\times {10}^{8}m/s$.

Answer-(D)