Download AKTU B-Tech 1st Sem 2017-2018 REC101 Basic Electronics Question Paper

Download AKTU (Dr. A.P.J. Abdul Kalam Technical University (AKTU), formerly Uttar Pradesh Technical University (UPTU)) B-Tech 1st Semester (First Semester) 2017-2018 REC101 Basic Electronics Question Paper

Printed pages: 03 Sub Code: REC101
Paper Id: 3 0 0 1 Roll No:
B.TECH
(SEM 1) THEORY EXAMINATION 2017-18
BASIC ELECTRONICS
Time: 3 Hours Total Marks: 70
Notes:
1. Attempt all Sections. If require any missing data; then choose suitably.
2. Any special paper specific instruction.
SECTION A
1. Attempt all questions in brief. 2 x 7 = 14
A. An operational amplifier has a differential gain of 103 and 100, input voltages are 120uV and 80uV,
and determine output voltage.
B. What is ripple factor? What is the value of RF for half wave and full wave rectifier?
C. Why BJT is called current controlled device?
D. State the advantage of digital instruments over analog instruments.
E. List the ideal characteristics of op?amp.
F. What is modulation index? Draw the amplitude spectrum of AM wave.
G. What is trans?conductance in F ET? What is the relationship between gm and gmov
SECTION B
2. Attempt any three of the following: 7 x 3 = 21
A. Explain the following with clear diagram:-
i) Full wave voltage doubler.
ii) Bridge rectifier.
B. Draw the common emitter circuit and sketch the input and output characteristics. Also explain active
region, cutoff region and saturation region by indicating them on the characteristic curve.
C. Explain how Op?Amp can be used as
i) Integrator ii) Inverting Summer and iii) Voltage Follower
D. Explain with block diagram how DMM can measure AC and DC signals and various other electrical
parameters?
E. Draw the block diagram of communication system. Calculate the percentage power saving when one
side band and carrier is suppressed in an AM signal with modulation index equal to 1.

SECTION C
3. Attempt any one part of the following: 7 x 1 = 7
1)
A) Determine the range of Vi for the ?g. that will maintain the zener diode in ? 0n ? state?
1.1
H
?i-
'6 lm : h
- 2 1n u If,
4.
I "I = 3? "' ?, 1.: m ?u.
rm : ?-H rm?. L _
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B) Determine V0 for the circuit shown in ?g
I. 'II I:
1' ID at: H - - 4.1
+ [I I uF I 4?
hi
} 1| Rg 55- m
? : v
| - T ?
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I
I
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2) Explain the following:-
A) Tunnel Diode
B) Transition capacitance and diffusion capacitance
4. Attempt any one part of the following: 7 x 1 = 7
1) For the network of fig.
a) Determine RB and RE
b) Find VB, VCE, and VBC
2)
A) Explain the construction and working of N-charmel JFET. Draw the drain characteristic and
transfer curve.
B) Explain the construction and working of depletion MOSFET.

5. Attempt any one part of the following: 7 x 1 = 7
1)
A) Calculate the output voltage V0 0f the circuit.
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h 33 m
11? ?52
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47?}
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? L?m'h' "E"
B) Explain the following characteristics of an op?amp:-
i) CMRR
ii) slew rate
2) Derive an expression for voltage gain of inverting and non-inverting ideal operational ampli?er
con?gurations)
6. Attempt any one part of the following: 7 x 1 = 7
1) Draw and explain the block diagram of a ramp-type digital voltmeter (DVM).
2) A) Draw the general block diagram of CR0 and explain each block.
B) A Lissajous pattern on an oscilloscope is stationary) It has 5 vertical tangent values and 6
horizontal tangent values. The frequency of horizontal input is 1800Hz? Determine the frequency of
vertical input.
7. Attempt any one part of the following: 7 x 1 = 7
1) De?ne Amplitude Modulation) Derive the expression for AM modulated waveform. Define modulation
index of AM)
2) A certain AM transmitter radiates 9 KW with the carrier unmodulated and 10.125 KW when the carrier
is modulated. Calculate the modulation index) If another sine wave is simultaneously transmitted with the
modulation index 0.4, determine the total radiated power)