2010 Jawaharlal Nehru Technological University, Hyderabad Code No: 09A1BS02 R09 Set No. 3 I B.Tech Regular Examinations,June 2010 ENGINEERING PHYSICS Question paper
Code No: 09A1BS02 R09 Set No. 3
I B.Tech Regular Examinations,June 2010
ENGINEERING PHYSICS
Common to CE, ME, CHEM, BME, IT, MECT, MEP, AE, BT, AME, ICE,
E.COMP.E, MMT, ETM, EIE, CSE, ECE, EEE
Time: 3 hours Max Marks: 75
Answer any FIVE Questions
All Questions carry equal marks
1. (a) Explain Fermi-Dirac distribution function. Illustrate the e ect of temperature
on the distribution.
(b) Derive an expression for density of states of an atom. [8+7]
2. (a) Derive the expressions for:
i. Acceptance angle and
ii. Numerical aperture of an optical ber.
(b) Describe the di erent types of bers by giving the refractive index pro les and
propagation details. [8+7]
3. (a) What are Brillouin zones? Explain using E-K diagram.
(b) De ne e ective mass of an electron. Explain its physical signi cance.
(c) What is a hole? List out the properties of a hole. [5+5+5]
4. (a) Write notes on `point defects' in crystals..
(b) Derive the expression for the density of Frenkel defects in a metallic crystal.
(c) What is Burgers vector? Explain. [5+5+5]
5. (a) Describe the di erent methods of acoustic quieting.
(b) Describe various method to achieve soundproo ng. [7+8]
6. (a) Explain the terms:
i. Magnetic induction,
ii. Magnetic susceptibility,
iii. Permeability of a medium and
iv. Intensity of magnetization.
(b) What are hard and soft magnetic materials? Give their characteristic proper-
ties and applications.
(c) A paramagnetic material has a magnetic eld intensity of 104 amp/m. If the
susceptibility of the material at room temperature is 3.7 10??3. Calculate
the magnetization and
ux density of the material. [6+5+4]
7. (a) What do you understand by Miller indices of a crystal plane?
(b) Show that in a cubic crystal the spacing (d) between consecutive parallel
planes of Miller indices (h k l) is given by d = a (h2 + k2 + l2)??1=2.
(c) NaCl crystals have FCC structure. The density of NaCl is 2.18 gm/cm2.
Calculate the distance between two adjacent atoms. (Molecular weight of
NaCl = 58.5). [4+7+4]
8. (a) Derive an expression for density of electrons in intrinsic semiconductors.
(b) Explain the variation of Fermi level with temperature in the case of p-type
semiconductors.
(c) If the e ective mass of holes in a semiconductor is 5 times that of electrons, at
what temperature would the Fermi level be shifted by 15% from the middle of
the forbidden energy gap? [Given that the energy gap for the semiconductor
is 1.20 eV]. [7+4+4]
KEYWORDS:JNTU ENGINEERING PHYSICS,JNTU ENGINEERING PHYSICS QUESTION PAPER,JNTU,JNTU QUESTION PAPER,JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD MCA-IV SEMESTER SUPPLEMENTARY EXAMINATIONS JULY JNTU ENGINEERING PHYSICS
Code No: 09A1BS02 R09 Set No. 3
I B.Tech Regular Examinations,June 2010
ENGINEERING PHYSICS
Common to CE, ME, CHEM, BME, IT, MECT, MEP, AE, BT, AME, ICE,
E.COMP.E, MMT, ETM, EIE, CSE, ECE, EEE
Time: 3 hours Max Marks: 75
Answer any FIVE Questions
All Questions carry equal marks
1. (a) Explain Fermi-Dirac distribution function. Illustrate the e ect of temperature
on the distribution.
(b) Derive an expression for density of states of an atom. [8+7]
2. (a) Derive the expressions for:
i. Acceptance angle and
ii. Numerical aperture of an optical ber.
(b) Describe the di erent types of bers by giving the refractive index pro les and
propagation details. [8+7]
3. (a) What are Brillouin zones? Explain using E-K diagram.
(b) De ne e ective mass of an electron. Explain its physical signi cance.
(c) What is a hole? List out the properties of a hole. [5+5+5]
4. (a) Write notes on `point defects' in crystals..
(b) Derive the expression for the density of Frenkel defects in a metallic crystal.
(c) What is Burgers vector? Explain. [5+5+5]
5. (a) Describe the di erent methods of acoustic quieting.
(b) Describe various method to achieve soundproo ng. [7+8]
6. (a) Explain the terms:
i. Magnetic induction,
ii. Magnetic susceptibility,
iii. Permeability of a medium and
iv. Intensity of magnetization.
(b) What are hard and soft magnetic materials? Give their characteristic proper-
ties and applications.
(c) A paramagnetic material has a magnetic eld intensity of 104 amp/m. If the
susceptibility of the material at room temperature is 3.7 10??3. Calculate
the magnetization and
ux density of the material. [6+5+4]
7. (a) What do you understand by Miller indices of a crystal plane?
(b) Show that in a cubic crystal the spacing (d) between consecutive parallel
planes of Miller indices (h k l) is given by d = a (h2 + k2 + l2)??1=2.
(c) NaCl crystals have FCC structure. The density of NaCl is 2.18 gm/cm2.
Calculate the distance between two adjacent atoms. (Molecular weight of
NaCl = 58.5). [4+7+4]
8. (a) Derive an expression for density of electrons in intrinsic semiconductors.
(b) Explain the variation of Fermi level with temperature in the case of p-type
semiconductors.
(c) If the e ective mass of holes in a semiconductor is 5 times that of electrons, at
what temperature would the Fermi level be shifted by 15% from the middle of
the forbidden energy gap? [Given that the energy gap for the semiconductor
is 1.20 eV]. [7+4+4]
KEYWORDS:JNTU ENGINEERING PHYSICS,JNTU ENGINEERING PHYSICS QUESTION PAPER,JNTU,JNTU QUESTION PAPER,JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD MCA-IV SEMESTER SUPPLEMENTARY EXAMINATIONS JULY JNTU ENGINEERING PHYSICS