Question

The drift velocity of electron in a copper wire of length 2m under the application of a potential difference of 200 V is 0.5 ms^-1. Their mobility is _______. (in m² V^-1 s^-1)

Options

• 2.5 × 10^-3

• 2.5 × 10^-2

• 5 × 10^-2

• 5 × 10^-3

Answer 1

The drift velocity of electron in a copper wire of length 2m under the application of a potential difference of 200 V is 0.5 ms^-1. Their mobility is 5 × 10^-3.

Explanation:

Mobility `mu = "v"_"d"/"E"`

V = 200 V   v_d = 0.5 ms-1  ℓ = 2 m

As we know: E = `"V"/ℓ => mu = "v"_"d"/"V" xx l`

`mu = 0.5/200 xx 2`

`= 5 xx 10^-3 " m"^2 "V"^-1 "s"^-1`