# Basic Physics 5

First Year Engineering Common to all Branches: Basic Physics 5

Subject: Basic Physics 5

Part 5: List for questions and answers of Basic Physics

Q1. The majority charge carriers in n-type semiconductor are
a) free electrons
b) holes
c) both holes and free electrons
d) neither free electrons nor holes

Q2. According to quantum free electron theory the electrons follow …… distribution of energy
a) binomial
b) Maxwell-Boltzmann
c) Fermi-Dirac
d) Bose-Einstein

Q3. The resistance of a conductor of unit length and unit cross section area is known as……
a) resistivity
b) conductivity
c) resistance
d) conductance

Q4. The unit of resistivity is
a) ohm
b) ohm/m
c) ohm-m
d) mho/m

Q5. Which of the following equations for mobility is correct?
a) μ = νd/E
b) μ = σ/ne
c) μ = 1/neρ
d) all of these

Q6. The equation for current density is J=
a) nevd
b) neavd
c) nea
d) none of these

Q7. If an electric field of 10 V/m applied to n-type germanium in which the mobility of free electrons is 3800 cm2/V-s, the drift velocity of electrons will be……….m/s.
a) 38000
b) 38
c) 3.8
d) 0.38

Q8. If an electric field of 10 V/m applied to p-type germanium gives rise to a drift velocity of 1.7 m/s for the holes, the mobility of holes is …..cm^2/V-s.
a) 1.7
b) 17
c) 170
d) 1700

Q9. The Hall coefficient is given by RH = ….
a) nq
b) 1/nq
c) n/q
d) q/n

Q10. Identical particles for which the spin is an odd integer multiple of half which cannot be distinguished from one another obey ………… distribution for energy.
a) binomial
b) Maxwell – Boltzmann
c) Fermi-Dirac
d) Bose-Einstein

Q11. Identical particles with 0 or integer spins with overlapping wave functions which cannot be distinguished from one another obey ………… distribution for energy.
a) binomial
b) Maxwell – Boltzmann
c) Fermi-Dirac
d) Bose-Einstein

Q12. The value of Fermi function at T = 0 K for E>EF is ……….
a) 0
b) 1
c) 0.5
d) 0.75

Q13. The value of Fermi function at T = 0 K for E is less than EF is ……….
a) 0
b) 1
c) 0.5
d) 0.75

Q14. The value of Fermi function at T = 0 K for E=EF is ………
a) 0
b) 1
c) 0.5
d) 0.75

Q15. In an intrinsic semiconductor, the Fermi level lies….
a) just above the valance band
b) just below the conduction band
c) at the centre of forbidden band
d) none of the above

Q16. If at a particular temperature, the energy is increased, the Fermi function……..
a) Increase
b) decrease
c) remains constant
d) initially increase and the decreases

Q17. When forward bias is applied to a p-n junction diode the Fermi level in n type …… with respect to Fermi level in p type
a) rises
b) falls
c) remains at the same level
d) initially rises and then falls

Q18. When reverse biased voltage is applied to a a p-n junction diode, the width of depletion layer
a) increases
b) decreases
c) remains constant
d) initially decrease and then increases

Q19. The number of semiconductor layers in a transistor is …….
a) 0
b) 1
c) 2
d) 3

Q20. In the Hall effect, the magnetic field is applied ………
a) in the direction of current
b) opposite to direction of current
c) either in or opposite to direction of current
d) perpendicular to direction of current

Part 5: List for questions and answers of Basic Physics