Kurukshetra University 2009 B.Tech Electronics and Communications Engineering Elements of electroics engineering (eee) - Question Paper
ELEMENTS OF ELECTROICS ENGINEERING
PAPER : EL-101 E
Roll No Total Pages : 4
BT-I/D09
ELEMENTS OF ELECmONlCS ENGINEERING Paper: EL-IOJ (E)
[Maximum Marks : 75
Time : Three Hours]
: Attempt any five questions, selecting one question from each unit. Q. No. 9 Is compulsory*
(a) The mobilities of free electrons and holes in pure germanium are 0-3S and 0. J 8 m-/Vs, The coirespondmg values for pure silicon are 0*13 and 0.05 irr/Vs respectively. Determine the value of intrinsic resistivity for both germaniuni and silicon. Assume that r for germanium is 2-5x1and for silicon 1.5 x lOnr-at room tem peratu re, 7.5
i.
(b) Show how zener diode can be used in a voltage regulator circuit. Explain voltage regulating capability of the circuit when (i) the load nfcsistance increases;
yX
(ii) the input voltage decreases, 7.5
(a) Draw the circuits of centre tap lull wave rectifier and explain its operation with the help of waveforms, 7,5
(b) Discuss fhe construction of LED and its characteristics.
3, (a) The transistor in the circuit shown below has [i - 50 and exhibits a Vjj of 0.7 V, Find terminal voltage Vf) and Ij- 7,5
+ 10 V |1D kQ
10kQ I u
-vR
|-WV
+
0.7 V
{b) Co mpa re CB, CE and CC con figu ration s. Wh i ch o f them is beSL suited for amplification, and why ? 7,5
4. ta) x.plain the working of a transistor as an amplifier. Use
Common base configuration for the purpose, 7,5
(b) What is the need of biasing in transistor 7 Discuss the emitter biased circuit with the help of a neat diagram,
UNIT-III
5. Draw the circuit of a differential amplifier and explain its trail sfer c h aract eri si ics. 7,5
JtfT How do you use an Opamp as an integrator ? Draw the circuit and obtain the expression for the output volLage.
' 7,5
6. (a) What is the difference between a summing amplifier
and an adder circuit ? Explain with the help of neat diagrams. 7.5
bf What*tto you mean by CMKR of an Opzimp ? What are the charactcristies of an ideal Opamp 7 7,5
UN1T-IV
7. (n) Give the construction details of a TRIAC and draw* its characteristics. Li si few applications of the TRIAC, 7.5
ibi Skeich the cross-seclion of P channcl enhancement MOSFFT and givc (heir I wo circui! symbols. Draw their
static drain characteristics and transfer characteristics.
7.5
fi. tjjiii Define (i) Pinch-ot'f voltage, and (ii) Channcl ohmic resistance in case of FFT, 7,5
(J)) Give the construction details of an SCR and draw ils characteristics, Lis) few applications of SCR, 7,5
9, Attempt all the following :
In case of silicon p-n junction, when barrier potential reaches 0.7 V, the diffusion stops. Why ?
How can you check the polarity of the diode if the mark on its body is rubbed off or not visible ?
v(<3 The rectifier diodes are never operated in breakdown region. Why ?
t(il) Explain why a transistor action cannot be achieved by connecting two diodes back to back.
(t:) Why FFT is known as a unipolar device ? . 8003/8900/KD/2 3 iP.T.O
(f) A negative feedback amplifier tuis <5 closed loo[3 gain Af = 1000 and open loop gain A = 10s- What is the feedback factor ?
(gf' What is the principle of resistance measurement in digital multimeter '?
Discuss V-l characteristics of UJT- 5
SOf)3/R900/ttD/2 4
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| Earning: Approval pending. |
