**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**

Q1. Answer: a

Q2. Answer: c

Q3. Answer: a

Q4. Answer: c

Q5. Answer: d

Q6. Answer: a

Q7. Answer: c

Q8. Answer: d

Q9. Answer: b

Q10. Answer: c

Q11. Answer: b

Q12. Answer: a

Q13. Answer: b

Q14. Answer: c

Q15. Answer: c

Q16. Answer: c

Q17. Answer: as

Q18. Answer: a

Q19. Answer: d

Q20. Answer: d