# Conductivity of a Semiconductor MCQ’s

This set of Electronic Devices & Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Conductivity of a Semiconductor”.

1. Which of the following expressions doesn’t represent the correct formula for Drift current density?
a) J=σE
b) J=qnµE
c) J=µE
d) None

2. Does a semiconductor satisfy the ohm’s law?
a) True
b) False

3. What is the SI unit of conductivity?
a) Ωm
b) (Ωm)-1
c) Ω
d) m

4. In which range of temperature, freeze out point begins to occur?
a) Higher range
b) Lower range
c) Middle range
d) None

5. What is the voltage difference if the current is 1mA and length and area is 2cm and 4cm2 respectively?(ρ=2Ωm)
a) 0.025V
b) 25V
c) 0.25V
d) None

6. What is the electric field when the voltage applied is 5V and the length is 100cm?
a) 0.5V/m
b) 5V/m
c) 50V/m
d) None

7. Which of the following expression represents the correct formula for the conductivity in an intrinsic material?
a) ρ=e(μn+μp )ni
b) σ=e(μn+μp )ni
c) σ=1/(e(μn+μp )ni)
d) ρ=1/(e(μn+μp )ni)

8. Is resistivity is a function of temperature?
a)True
b)False

9. Calculate the average random thermal energy at T=300K?
a) 0.038eV
b) 3.8eV
c) 38eV
d) 0.38eV

10.

In the above figure, a semiconductor having an area ‘A’ and length ‘L’ and carrying current ‘I’ applied a voltage of ‘V’ volts across it. Calculate the relation between V and A?
a) V= ((ρ*L)/A)*I
b) V= ((ρ*A)/L)*I
c) V= ((ρ*I)/(A*L))
d) V=((ρ*I*A*L)