Question

A potential difference of 10 V is applied across a
conductor of length 5 cm. If drift velocity of electron is
2 x 10-4 m/s, then electron mobility in (m2v-1s-) will
be
4 x 10-6
2x 10-4
10-6
4 x 10-4​

Answer 1

Answer:

5×10

−6

m

2

V

−1

s

−1

We know,

E=

d

V

Given,

V=5v

d=10cm=0.1m

V

d

=2.5×10

−2

cms

−1

=2.5×10

−4

ms

−1

∴E=

0.1

5

=50Vm

−1

Mobility of an electron is it's drift velocity per unit electric field.

∴μ=

E

V

d

μ=

50

2.5×10

−4

=5×10

−6

m

2

V

−1

s

−1

Answer 2

Given: A potential difference of 10V is applied across conductor of length 5 cm. Drift velocity of electron is 2* 10^-4 m/s.

To find: Electron mobility in conductor

Explanation: Length= 5 cm = 0.05 m

Potential difference= 10V

The relation between electric field (E), potential difference (V) and length(l) is as follows:

E= V/d

= 10/0.05

= 200 V/m

Now, drift velocity of electron is 2* 10^-4 m/s and electric field is 200 V/m

The relation of drift velocity (v) , electric field (E) and electron mobility (u) is:

u= v/E

= 2* 10^-4/200

= 10^-6 m^2 / Vs

Therefore, the electron mobility of the electron in the conductor is 10^-6 m^2/Vs.