Name of the University : Alagappa University
Degree : B.Sc
Department : Electronics
Subject Code/Name : SemiConductor Devices
Semester : II
Document Type : Model Question Papers
Website : alagappauniversity.ac.in
Download Model/Sample Question Paper : Nov 2010 : https://www.pdfquestion.in/uploads/alagappauniversity.ac.in/4014.-B.Sc.%20Electronics%20%5BNon-CBCS%5D.pdf
Alagappa University SemiConductor Devices Question Paper
1. What is a semiconductor – Write a note on intrinsic semiconductor.
2. Explain the action of Zener diode as a Voltage regulator.
3. Explain the construction of MOSFET.
Related : Alagappa University Circuits And Networks Analysis And Synthesis B.Sc Model Question Papers : www.pdfquestion.in/3979.html
4. Write a note on some important applications of SCR.
5. Discuss about LCD.
Part – B : (5 × 10 = 50)
Answer all questions.
6. (a) Discuss the effect of temperature on P and N type carriers.
(Or)
(b) Explain the formation of N-type semiconductor.
7. (a) Draw the circuit of transistor amplifier and explain its working.
(Or)
(b) Explain the characteristics of Zener diode in Forward and Reverse bias conditions.
8. (a) Explain the working of MOSFET.
(Or)
(b) Explain the construction and working of P-channel FET.
9. (a) Describe the working principle of UJT.
(Or)
(b) Write a note on SCR. Give its characteristics.
10. (a) Explain the working of LED.
(Or)
(b) Write a note on LDR.
Part – C : (3 × 10 = 30)
Answer any three questions.
11. What do you understand by a Extrinsic Semiconductor ? Explain in detail, the formation of P-type semiconductor.
12. Discuss the behaviour of a PN junction under forward and reverse bias conditions.
13. Explain the V-I characteristics of FET.
14. What is a UJT ? Describe its working as a relaxation oscillator ?
15. Give the construction, working and uses of photo diode.
Digital Principles & Applications
(Non-CBCS—2004 onwards)
Time : 3 Hours
Maximum : 100 Marks
Part – A (5 × 4 = 20)
Answer all questions.
1. Explain the following :
(a) BCD code ; (b) ASCII code.
2. State and prove De Morgan’s theorem.
3. Explain Demultiplexer.
4. Discuss the working principle of RS flip-flop.
5. Explain the working of a ripple counter.
Part – B : (5 × 10 = 50)
Answer all questions.
6. (a) Add the binary equivalent numbers of the following decimal numbers 20110 and 22510.
(Or)
(b) Express the following binary numbers in Gray code : (i) 1000 (ii) 0110 (iii) 1001 (iv) 0111 (v) 0101.
7. (a) Draw the logic symbol, write down the Boolean expression and truth table of the following gates : (i) AND (ii) OR (iii) NOT (iv) NAND (v) NOR
(Or)
(b) Implement the logic functions NOT, OR and AND using NAND gates only.
8. (a) Write a detailed note on SOP.
(Or)
(b) Explain the function of full adder and full subtractor.
9. (a) What is shift register ? Discuss its types.
(Or)
(b) Explain Synchronous up and down counter.
10. (a) Explain the working of binary ladder resistor network.
(Or)
(b) Explain the working of any one type of A/D converter.
Part – C : (3 × 10 = 30)
Answer any three questions.
11. Add the given binary numbers 11110101 and 10100011 and obtain the hexadecimal equivalent of the sum.
12. Implement the following Boolean equation using NAND gates.
13. Simplify the following Boolean expression using K-map.
14. Describe the working of a ring counter.
15. In a D/A converter if Rf = R and the full scale voltage is 10 V. Calculate the output voltage corresponding to the inputs. (i) 0110 (ii) 1100.
Optical Communication
(Non -CBCS—2004 Onwards)
Time : 3 Hours
Maximum : 100 Marks
Part – A (5 × 4 = 20)
Answer All questions.
1. Write a note on multimode dispersion.
2. Write short note on power density distribution.
3. Explain the working principle of single mode diffraction feedback lasers.
4. Describe the working of star network with an example.
5. Discuss the merits of the fibers.
Part – B : (5 × 10 = 50)
Answer All questions.
6a. Describe the different types of scattering losses in fibers.
(OR)
b. A silica optical fiber has a core refractive index of 1.49 and a cladding refractive index of 1.42. Calculate (i) the critical angle (ii) the numerical aperture (iii) the acceptance angle of the fiber.
7a. Explain the characteristics of HE11 mode propagation.
(OR)
b. Explain the mechanism of Intramode dispersion in a multi mode step Index fiber.
8a. Describe the construction and working of Avalanche photodiode.
(OR)
b. Discuss the instrinsic and impurity semiconductors.
9a. Explain the local area network and their configuration.
(OR)
b. Discuss the following terms : Hetero junction, Efficiency.
10a. Explain the growth of optical fiber communication technology from first generation to current status.
(OR)
b. Explain the working of a LED and the LASER.
Part – C : (3 × 10 = 30)
Answer any Three questions.
11. With a neat block diagram, explain the basic optical fiber communication.
12. Explain the working principle of surface LED and Edge LED.
13. Derive an expression for numerical aperture in the case of graded Index fiber.
14. Find the cut-off wavelength of the step Index multimode fiber having core radius 25m, refractive index of core is 1.48, V number – 25 and the refractive index profile is 0.01.