Saturday, 21 February 2015
Time: 3 hours
Total marks: 100
Q 1. Attempt any Four:
A. Describe and discuss various features of ICs with respect to discrete integral circuits.
B. What are the various steps involved in the manufacturing of monolithic IC.
C. Why oxidation is done? Explain the chemistry of oxidation and kinetics of oxide growth.
D. A silicon wafer with p type doping of 1015 is heated at 1000⁰ C for 1 hour in day oxygen. How much oxide has been grown?
E. Describe a CZ furnace. What are its advantages?
F. All modern silicon MOSFET’ s are fabricated on <100> oriented Si substrate. Why?
Q 2. Attempt any four:
A. What are the process variables which affect the diffusion process? Explain.
B. What is optical growth? What is the advantage of epitaxial process over diffusion and Czo kralski process?
C. What is Fick’ s Law? Explain it’s important in theory of diffusion.
D. What is the MBE system? Explain with diagram.
E. Write short note on
i. Photo mask and photo resist.
ii. Photo lithography techniques.
F. Does the thickness of the epitaxial wafer pose a problem in epitaxial processing from a stress view point? Discuss your answer.
Q 3. Attempt any Two:
A. Compare X- ray and ion- beam lithography.
B. What is etching? Explain its different types and write advantages & disadvantages of each.
C. What are proximity and projection printers? Explain.
Q 4. Attempt any Two:
A. What is metallization? Write its application and problem areas associated with it. Explain in brief.
B. Why depletion MOSFET is so called? Explain the operating and characteristics of n- channel depletion type MOSFET with suitable sketches.
C. (1) Draw the block diagram of 1 bit SRAM.
(2) Sketch the circuit diagram of a ratio less MOS inverter. Explain its operation.
Q 5. Attempt any Two:
A. What are yield losses in VLSI? How they are modeled? What is its role in VLSI testing?
B. Explain VLSI assembly technologies.
C. Describe the commonly used VLSI testing procedures.
Thursday, 15 January 2015
B.tech Examination papers dec 2014
sub - Switchgear and protection
Utu previous year question papers
uttarakhand technical university previous question papers
Time : 3 hrs
Q1: Attempt any four :
- Explain static relay and write its merits and demerits.
- Explain electromagnetic impedance relay.
- What are the various types of over current relays? Discuss their are of applications.
- Explain Directional Over-current relay?
- The current rating of a relay is 5A. PSM=2, TSM=0.3, CT ratio=400/5, fault current= 4000A. Determine the operating time of the relay. At TMS= 1, operating time various PSM are:
PSM= 2 4 5 8 10 20
operating time in seconds= 10 5 4 3 2.8 2.4
Utilization of Electrical Energy and Traction. UTU (uttrakhand technical university previous year question papers)
B.tech question papers
sub- Utilization of Electrical Energy and Traction.
UTU (uttrakhand technical university
previous year question papers)
Q1: Attempt any four:
- What are the advantages of induction heating? Give classification of various heating methods.
- What is Ajax-Wyatt Furnace? Describe construction, principle of operation and application of this furnace.
- Discuss advantages of electrically produced heat. State the properties of a heating element used for this heating.
- Explain with help of neat sketch the working of Ajax Wyatt furnace.
- A 40KW 3 phase 400v, resistance oven is to employ nichrome strip 0.25mm thick for the three star-connected heating elements. If the wire temperature is to be 1200C and that of the charge is to be 800C, estimate a suitable width for the strip. Assume emissivity= 0.9 and radiating efficiency=0.5. Also determine the temperature of the wire when the charge is cold.
- What are the factors which limit the choice of frequency in induction and dielectric heating?