A cylindrical conductor of length 2 m and area of cross-section 0.2 mm2 carries an electric current of 1.6 A when its ends are connected to a 2 V battery. Mobility of electrons in the conductor is 10-3 m2/V s. The value of is : (electron concentration = 5 1028 /m3 and electron charge = 1.6 10-19 C)
Answer
1
Solution
Drift speed: I = neAvd vd = IneA
vd = 1.65 1028 1.6 10-19 0.2 10-6
vd = 1.61.6 103 = 10-3 m/s
Electric field in the conductor: E = Vl = 22 = 1 V/m
Mobility: = vdE = 10-31 = 1 10-3 m2/V s
= 1
Answer: 1