FUNDAMENTAL OF ELECTRONICS ENGINEERING 2013, B.Tech 2nd Semester exam paper of Uttarakhand Technical University

FUNDAMENTAL OF ELECTRONICS ENGINEERING 2013, B.Tech 2nd Semester exam paper of UTU

FUNDAMENTAL OF ELECTRONICS ENGINEERING

SEM-II, 2013

B TECH QUESTION PAPER

UTTARAKHAND TECHNICAL UNIVERSITY

Time: 3 Hours

Total Marks: 100

Attempt any four parts of the following:

1. Define Semiconductor materials on the basis of energy band diagram with an example.
2. How electron-hole pairs are generated. Explain the working of different forms of semiconductors.
3. Why Si is preferred over Ge for manufacturing of electronics devices. How Semiconductors diode behaves as the switch.
4. Explain the effect of temperature on I-V characteristics of the p-n junction diode.
5. Differentiate between extrinsic and intrinsic semiconductor on the basis of impurity present in them.
6. Explain the working of Semiconductor diode at different biasing conditions, no bias, forward bias & reverse bias condition.

Attempt any four parts of the following:

1. Explain full wave bridge rectifier.
2. Prove that efficiency of full wave rectifier is 81%.
3. The reverse saturation current of a silicon diode in 3 nA at 27oC find-
   (i) Reverse saturation current at 82o
   (ii) Forward current at 82o C if the forward voltage applied is 82o C.
4. Sketch Vo for the circuit shown below D1 and D2 are silicon diodes.
   
5. Determine Vo for network given below.
   
6. Explain Voltage Doublers or Voltage Tripler with neat diagram.

Attempt any two parts of the following:

1. (i) Explain Zener diode, draw its symbol and V-I characteristics.
   (ii) In a Zener voltage Regulator find the range of RLand IL for Load voltage to be constant.
   
2. Draw a Voltage Regulation that will maintain an output voltage of 20V across a 1KΩ load with an input that will vary between 30 and 50 V. That is determining the proper value of series Resistance (Rs) and maximum current IZM.
3. Explain Zener Diode application as the shunt regulator.

Attempt any two parts of the following:

1. (i) Derive the relation between α & β of the transistor, also calculate β for given α= 0.95.
   (ii) Explain potential divider biasing of the transistor.
2. (i) Explain the working of NPN transistor at no bias and active mode condition.
   (ii) What is closed loop non-inverting amplifier, derive an expression for it.
3. (i) The BJT amplifier has hfe= 100, VBE = 0.007 V, ICO = 0. Calculate the value of R1 and RC. Such that IC =1 mA and VCE = 2.5V.
   
   (ii) For the following, as shown in the following, determine the output voltage vo if the input voltage vi = 1.2 V.
   

Attempt any two parts of the following:

1. (i) Write down characteristics of ideal OP-AMP.
   (ii) What is close loop non inverting amplifier, derive expression for it.
2. (i) Convert the following numbers:
   (a) (4021.25)10= ( )2
   (b) (101010.10)4 = ( )8
   (c) (23.AB)16 = ( )2
   (d) (111011)2 = ( )gray code
   (v) (23.53)10 + (23.58)8 = ( )10
   (ii) Minimize the following Boolean function and draw its logic diagram using minimum universal gates.
3. Explain the construction and working of n-channel enhancement type MOSEFET. Also draw its drain and transfer characteristics of the same.