physics pass 6th sem 2016 previous year Bsc question paper | Assam University
J16-860/1327 2016/SEM/EVEN/PHSP-601/3
TDC Even Se
mester Exam., 2016
PHYSICS
Pass
( 6th Semester )
Paper No. : PHSP-601
( Crystallography and Electronics)
Full Marks: 35
Pass Marks: 12
Time: 2 hours
The figures in the margin indicate full marks
for the questions
Answer five questions, taking one from each Unit
UNIT-I
1. (a) Explain the following terms used in crystallography:
(i) Unit cell
(ü) Primitive cell
(b) Explain how Miller indices of a crystal plane are determined.
2. (a) Explain space lattice. What is meant bysymmetry operations in crystals?
(b) Show that, in a cubic crystal with latticeconstant a, the interplanar spacingbetween two adjacent parallel planes ofMiller indices (h, k, l) is given by
d=h/(h^2+k^2+l^2)
UNIT-II
3. Describe the seven systems of crystals withsuitable diagrams.
4. (a) Deduce Bragg's law of diffraction incrystals, 2dsin θ n, where thesymbols have their usual meanings.
(b) Explain the following
(i) Bravais lattice
(iü) Reciprocal lattice
UNIT-III
5. Obtain Child Langmuir law in connectionwith space charge limited current in a diodevalve.
6. (a) Define plate resistance, mutualconductance and amplification factor ofa triode valve. Explain graphically how atriode valve amplifies an AC input signal
(b)Calculate the plate resistance of a triodevalve having mutual conductance1.5 mA/volt and amplification factor
UNIT-IV
7. (a) Name twocommonly usedsemiconductors. How are p-type andn-type semiconductors formed?
(b) Explain with necessary diagram thecharacteristic curve of a forward-biasedjunction diode.
8. (a) Explain the working of a transistor asan amplifier in CE mode.
(b) Explain DC and AC load line.
UNIT-V
9. (a) Explain the concept of feedback inamplifiers.
(b) With a neat diagram, explain theworking of a Hartley oscillator.
10. (a)Define NAND and NOR gates. Constructtruth tables for two input NAND andNOR gates.
(b) Draw the circuit diagram of a NOT gateand explain its working.
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