Code No: 210551 II B.Tech I- Semester Examination November/December 2002. ELECTRONICS DEVICES AND CIRCUITS (Computer Science & Engineering)
c)
2 a) b)
c) 3 a)
b)
4 a)
Explain how reverse biased diodes are used as varactor diodes. Sketch its equivalent circuit and explain. Explain hall effect and how it can be applied to measure the charge density ‘e’ and mobility ‘’ of change carrier Derive an expression for the electro-magnetic defection sensitivity of a C.R.T. Explain the working of a PNP transistor and derive expressive for its ‘emitter injection efficiency” and “base-transport factor” in terms of the physical parameters of the transistor. A Ge transistor with the 0 = 0.98 gives a reverse saturation current Ico = 10 A in CB configuration. When the transistor is used in CE configuration with a base current of 0.22 m A, calculate the collector current. Derive the formula used. Sketch the static drain and transfer characteristics of a JFET and justify their nature. What is pendi-off voltage and mark it on the characteristics. Explain how do you obtain JFET parameters from the above characteristics. AJFET has Vp = -4.5v, IDSS=16 mA and IDS=4 mA. Determine Vas required and value of “Im” at this value of vas.
nt
b) c)
or ld
b)
uW
1 a)
Max. Marks: 70 Answer any Five questions All questions carry equal marks ---Explain the generation and recombination of charges with regard to semiconductors. Draw the V-I characteristics of a PN junction diode and label the important parameters on it. Explain the temperature dependence of these V-I characteristics. What is the transition capacitance of a PN junction diode? How does it vary with the applied volluge . What is the order of its magnitude?
.in
Time: 3 hours
Explain the basic construction of an SCR. Explain its principle of operation using two transistor model. Sketch its V-I characteristics. Define ‘Hold current ‘ and latch current’ and mark them on the characteristics. Explain its turn-off mechanism. Describe the fabrication of (i) Enhancement move MOSFET aml (ii) MOS capacitor with neat cross-sectional diagrams in monolithic Integrated circuits. Contd…2.
Aj
5 a)
b)
Code No: 210551
c)
An amplifies uses a cascade of fan BJT stages suggest suitable choice of configuration for each stage, if it is to be a high gain amplifier with high input impedance and low output impedance. Justify an answer. In a self biased circuit comprising R2 = 90 kr, R1 = 10 kr, Vcc= 22.5v, RC = 5.6 kr and RE = 1.0 kr and a BJT with 0 = 55 and VBE = 0.6v. Find the operating point and ‘S’ of the circuit. Prove that for any amplifier configuration using a BJT the input impedance Ri is given by hi Ri = __________ 1-hr AV
.in
b)
OR
or ld
6 a)
-2
Explain how a Zener diode can be used as voltage regulator. Design a power supply for a local that requires 30 walts of power. The load voltage is 300V and the ripple voltage in the load should be less that 0.2v. Use an L-section fitter and critical value of inductance. Specify the required element values and input r.m.s voltage using a single phase bridge rectifier. Assume supply frequency of 504t.
8
Write short notes on the following: a) Back ward diodes b) Biasusing circuits for MOS FETS. c) Emitter follower amplifier d) Thermal run away in BJT amplifiers
b) Explain hall effect and how it can be applied to measure the charge density 'e' · and mobility 'μ' of change carrier · c) Derive an expression for the electro-magnetic defection sensitivity of a C.R.T. · 3 a) Explain the working of a PNP transistor and derive expressive for its 'emitter · injection efficiencyâ and âbase-transport ...
How do you manufacture calcium Ammonium nitrate? Explain. 6. Discuss once through process and partial recycle process of urea manufacture. 7. Describe the ...
4.a) What is a routing table? b) List the four major routing classifications and state the characteristics of each? 5.a) Describe UDP with its header format.
b) What is an harmonicity? How it explains the thermal expansion of solids? ... Discuss briefly the Debbyes's theory of lattice specific heat · 4.a) Derive an ...
1.a) With a neat diagram, explain the functionality of layers, protocols and interfaces. b) What is the ... Explain the following with reference to Transport layer:.
b) Calculate the available continuous power of a hydro-electric station from the ... b) With a neat diagram, explain the working of a nuclear power plant. 5 a) What ...
a) Two phase Locking protocol · b) Check ... 6.a) Explain Two phase locking with algorithms. b) What is ... b) What are the fields in update log record. Explain the ...
C/C distance between the gantry girders = 14m · Width of wheel base = 3m · Clear edge distance for the hook of the crane = 1m · Crane (EOT) capacity = 160KN.
5.a) With an appropriate example. Explain the electrical activity of a skeletal muscle. b) What are motor unit potentials? What are their role in Neuromuscular.
Lithium aluminium hydride · b) Pyrrole undergoes Electrophilic substitution reactions primarily at C-2 position. Explain. c) With suitable chemical equations, ...
b) List the advantages of diesel plants over other thermal power plants? 2 a) With a neat block diagram explain the governing system of a open cycle gas.
Write Euler's turbine equation and explain each terms in it. 2.a) Explain ... 5.a) Draw the schematic diagram of a simple gas turbine cycle and explain briefly the.
Code No.411405. -3-. Set No.1. 6.a) State Robert's theorem and explain its application. b) Obtain the cograte mechanism for a drag link mechanism (A drag link mechanism · has two cranks) · 7. What is Function generation? Explain in detail with ... th
b) A governor of the Proell type has each arm 250mm long. The pivots of the ... One wheel is situated at the centre of the shaft and the other at a distance .... energy to be stored in represented on the diagram by an area of 50 Sq. Determine.
Set No:1. 4.a) Define the term 'Maintainability' and establish its importance in reliability ... 5.a) Outline the maintainability program elements with an example of ...
glass borelate the above scale with celsius temperature scale. How is the asolute · temperature expressed in · o · V? 2.a) State the first law of thermodynamics ...
6.a) A cylindrical air receiver for a compressor is 1.5m in internal diameter and made · of plates 15mm thick. If the hoop stress is not to exceed 100 N/mm.
The state variable model of the plant is given by · X = AX + bU · Y = CX · With A = · 0 1 ; b = · 0 · c = · [1 · 0] · 0 â1 · 1 · obtain the discrete time state description for ...
b) What is the minimum energy, expressed in joules and in electron volts, required · to remove an electron from the surface of metallic potassium, the ...
a) Laser welding ... What are the main applications of Laser welding. b) Explain various ... welding: · i) Tungsten (ii) Copper (iii) Aluminium and (iv) Mild steel.
Retrying... Whoops! There was a problem previewing this document. Retrying... Download. Connect more apps... Try one of the apps below to open or edit this item. Instructions to Student-End Semester Examination (Higher Semester).pdf. Instructions to
Whoops! There was a problem loading more pages. Retrying... Whoops! There was a problem previewing this document. Retrying... Download. Connect more apps... Try one of the apps below to open or edit this item. Addendum - List of Examination Centre fo