Consider a conductor of length 0.5 m. A potential difference of 20V is applied across this conductor. If the drift velocity of electrons is given as 5.0 × 10^-4ms^-1, then determine the mobility of the electrons.(a) 5.25 × 10^18m^2V^-1s^-1(b) 5.25 × 10^-18m^2V^-1s^-1(c) 1.25 × 10^-5 m^2V^-1s^-1(d) 1.25 × 10^6m^2V^-1s^-1The question was asked during a job interview.My enquiry is from Current Electricity in portion Current Electricity of Physics – Class 12

Consider a conductor of length 0.5 m. A potential difference of 20V is

1.	Consider a conductor of length 0.5 m. A potential difference of 20V is applied across this conductor. If the drift velocity of electrons is given as 5.0 × 10^-4ms^-1, then determine the mobility of the electrons.(a) 5.25 × 10^18m^2V^-1s^-1(b) 5.25 × 10^-18m^2V^-1s^-1(c) 1.25 × 10^-5 m^2V^-1s^-1(d) 1.25 × 10^6m^2V^-1s^-1The question was asked during a job interview.My enquiry is from Current Electricity in portion Current Electricity of Physics – Class 12
Answer» Right answer is (c) 1.25 × 10^-5 m^2V^-1s^-1 The explanation: Mobility = \(\frac {DRIFT \, VELOCITY}{ELECTRIC \, field}\). Electric field = \(\frac {Voltage}{LENGTH} = \frac {20}{0.5}\) = 40Vm^-1. Mobility = \(\frac {Drift \, velocity}{Electric \, field} = \frac {5.0 \times 10^{-4}}{40}\) = 1.25 × 10^-5 m^2V^-1s^-1.

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