Download VTU ((Visvesvaraya Technological University) B.E/B-Tech 2019 July ( Bachelor of Engineering) First & Second Semester (1st Semester & 2nd Semester) 2014 June-July 10ELN15 Basic Electronics Question Paper
USN
10ELN 15/25
First/Second Semester B.E. Degree Examination, June/July 2014
Basic Electronics
Time: 3 hrs. Max. Marks:100
Note: 1. Answer any FIVE full questions, choosing at least two from each part.
2. Answer all objective type questions only in OMR sheet page 5 of the answer booklet.
:.-.
g.
3. Answer to objective type questions on sheets other than OMR will not be valued.
7
a
PART ? A
1 a. Choose the correct answers for the following : (04 Marks)
cd
42.
i) Zener diode can be used for rectification. This statement is
do u
O, A) true B) false
C) neither true nor false D) none of these
.. ...-
g g
ii) The maximum efficiency of full wave rectifier is
.0
ii A) 40.6% B) 60.4% C) 78.5% D) 81.2%
iv) If f Hz is the frequency of the input given to a half wave rectifier, the output frequency
?a at II,
?
will be
m- ..
0
A) 2f Hz B) f Hz C) 3f Hz D) 0.5f Hz
p. ' n
. ,.. .
r?
g
b. Draw and explain the VI ? characteristics of a Si-diode and Ge-diode. (06 Marks)
i
"5
c. With a neat circuit diagram, explain the working principles of full wave bridge rectifier and
1
show that the ripple factor = 0.48, and efficiency = 81.2%. (10 Marks)
a3 ees
Lu 8
5
,
1 g
-5 73
>, > 2 a. Choose the correct answers for the following :
? 0
(04 Marks)
'E 2. i) The current conduction in BJT is because of
s f
t
l II, A) electrons B) holes
O
?
ca.
C) both electrons and holes D) none of these
m
O ..;
.
.., ?'
ii) If a = 0.95, then the value of
13
of transistor is
8 A) 0.05 B) 19 C) 100 D) 120
4
.c
= ?
-
?
a' iii) Common collector arrangement is generally used for
,_.
u
8 7ii A) impedance matching B) voltage amplification
>,
C) current amplifier D) none of these
7
c
rr T
.
,
.- iv) The current relationship between two current gain in a transistor is
3-
B) 13 =
1 + a 1? a 1+13
O P
A) 13=
1
a
ot
C) 13 = D) 13 =
0 >,
8
1 ?a 1+a
1
3
c
-
.1
4J b. Draw input and output characteristics of an NPN transistor in common base configuration
0
z and explain.
(10 Marks)
t
;:
cs c. For a Silicon transistor a
d
, = 0.995, emitter current is 10 mA and leakage current 1,? is
O 0.511A. Find lc, IB, J3 and
Icro.
(06 Marks) sa.
-7.
P2
r
?
t, iii) The knee voltage of a silicon diode is
A) 0.3V B) 0.5V C) 0.7V D) none of these
1 of 3
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USN
10ELN 15/25
First/Second Semester B.E. Degree Examination, June/July 2014
Basic Electronics
Time: 3 hrs. Max. Marks:100
Note: 1. Answer any FIVE full questions, choosing at least two from each part.
2. Answer all objective type questions only in OMR sheet page 5 of the answer booklet.
:.-.
g.
3. Answer to objective type questions on sheets other than OMR will not be valued.
7
a
PART ? A
1 a. Choose the correct answers for the following : (04 Marks)
cd
42.
i) Zener diode can be used for rectification. This statement is
do u
O, A) true B) false
C) neither true nor false D) none of these
.. ...-
g g
ii) The maximum efficiency of full wave rectifier is
.0
ii A) 40.6% B) 60.4% C) 78.5% D) 81.2%
iv) If f Hz is the frequency of the input given to a half wave rectifier, the output frequency
?a at II,
?
will be
m- ..
0
A) 2f Hz B) f Hz C) 3f Hz D) 0.5f Hz
p. ' n
. ,.. .
r?
g
b. Draw and explain the VI ? characteristics of a Si-diode and Ge-diode. (06 Marks)
i
"5
c. With a neat circuit diagram, explain the working principles of full wave bridge rectifier and
1
show that the ripple factor = 0.48, and efficiency = 81.2%. (10 Marks)
a3 ees
Lu 8
5
,
1 g
-5 73
>, > 2 a. Choose the correct answers for the following :
? 0
(04 Marks)
'E 2. i) The current conduction in BJT is because of
s f
t
l II, A) electrons B) holes
O
?
ca.
C) both electrons and holes D) none of these
m
O ..;
.
.., ?'
ii) If a = 0.95, then the value of
13
of transistor is
8 A) 0.05 B) 19 C) 100 D) 120
4
.c
= ?
-
?
a' iii) Common collector arrangement is generally used for
,_.
u
8 7ii A) impedance matching B) voltage amplification
>,
C) current amplifier D) none of these
7
c
rr T
.
,
.- iv) The current relationship between two current gain in a transistor is
3-
B) 13 =
1 + a 1? a 1+13
O P
A) 13=
1
a
ot
C) 13 = D) 13 =
0 >,
8
1 ?a 1+a
1
3
c
-
.1
4J b. Draw input and output characteristics of an NPN transistor in common base configuration
0
z and explain.
(10 Marks)
t
;:
cs c. For a Silicon transistor a
d
, = 0.995, emitter current is 10 mA and leakage current 1,? is
O 0.511A. Find lc, IB, J3 and
Icro.
(06 Marks) sa.
-7.
P2
r
?
t, iii) The knee voltage of a silicon diode is
A) 0.3V B) 0.5V C) 0.7V D) none of these
1 of 3
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10ELN15/25
3 a. Choose the correct answ( "
r
te
i) Which of the following factor affects the Q-point stability?
A) I
co
B) coupling capacitor
C) emitter resistor D) bypass capacitor
ii) The inter section of the dc load line with given base current curve is the
A) h-point B) D-point C) Q-point D) none of these
iii) For an emitter follower, the voltage gain is
A) unity B) greater than unity C) less than unity D) zero
iv) The best biasing stability is achieved by using biasing method.
A) fixed B) collector to base C) voltage divider D) none of these
b. Explain the working of collector-to-base bias circuit using an NPN transistor and derive the
equation for IB. (08 Marks)
c. Define stability factor and discuss the factors that cause instability of biasing circuits.
(08 Marks)
(04 Marks)
4 a. Choose the correct answers for the following
i) FET is a controlled device.
A) voltage B) current
ii) PNPN device is an
A) UJT B) SCR
iii) used as a relaxation oscillator.
A) MOSFET B) SCR
iv) The intrinsic standoff ratio of UJT
A) equal to one
C) must be greater than unity
(04 Marks)
C) pulse D) power
C) MOSFET D) MODFET
C) BJT rek ) UJT
B) must be less than unity
D) must be zero
b. Explain the working of two transistor model of an SCR and obtain the expression for the
anode current.
c. Draw the equivalent circuit and VI-characteristic of UJT and explain it.
(08 Marks)
(08 Marks)
(04 Marks)
D) both A and B
B) 2TELC C) 2ic LC D)
2rcLC 2n-4:C
hi) With negative feedback, the bandwidth of an amplifier
A) decreases B) increases C) both A and B D) constant
iv) The magnitude voltage gain at half power frequencies of an RC coupled amplifier is
times maximum voltage gain.
A) 0.707 B) 7.07 C) 10 D) 17.06
b. Draw the frequency response of an RC-coupled amplifier and explain it. Mention its
advantages and disadvantages. (08 Marks)
c. Explain with the help of circuit diagram the working of an RC phase shift oscillator using
transistor.
(06 Marks)
d.
In a transistor colpitts oscillator having tank circuit parameters as ci = 0.001 ILE and
c? = 0.01 pF if L = 51AH, calculate the frequency of oscillations. (02 Marks)
PART ? B
Choose the correct answers for the following :
i) Oscillator uses type of feedback.
A) positive B) negative C) reverse
ii) The frequency of oscillations in an oscillator is given by
A)
1
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PDF Eraser Free
USN
10ELN 15/25
First/Second Semester B.E. Degree Examination, June/July 2014
Basic Electronics
Time: 3 hrs. Max. Marks:100
Note: 1. Answer any FIVE full questions, choosing at least two from each part.
2. Answer all objective type questions only in OMR sheet page 5 of the answer booklet.
:.-.
g.
3. Answer to objective type questions on sheets other than OMR will not be valued.
7
a
PART ? A
1 a. Choose the correct answers for the following : (04 Marks)
cd
42.
i) Zener diode can be used for rectification. This statement is
do u
O, A) true B) false
C) neither true nor false D) none of these
.. ...-
g g
ii) The maximum efficiency of full wave rectifier is
.0
ii A) 40.6% B) 60.4% C) 78.5% D) 81.2%
iv) If f Hz is the frequency of the input given to a half wave rectifier, the output frequency
?a at II,
?
will be
m- ..
0
A) 2f Hz B) f Hz C) 3f Hz D) 0.5f Hz
p. ' n
. ,.. .
r?
g
b. Draw and explain the VI ? characteristics of a Si-diode and Ge-diode. (06 Marks)
i
"5
c. With a neat circuit diagram, explain the working principles of full wave bridge rectifier and
1
show that the ripple factor = 0.48, and efficiency = 81.2%. (10 Marks)
a3 ees
Lu 8
5
,
1 g
-5 73
>, > 2 a. Choose the correct answers for the following :
? 0
(04 Marks)
'E 2. i) The current conduction in BJT is because of
s f
t
l II, A) electrons B) holes
O
?
ca.
C) both electrons and holes D) none of these
m
O ..;
.
.., ?'
ii) If a = 0.95, then the value of
13
of transistor is
8 A) 0.05 B) 19 C) 100 D) 120
4
.c
= ?
-
?
a' iii) Common collector arrangement is generally used for
,_.
u
8 7ii A) impedance matching B) voltage amplification
>,
C) current amplifier D) none of these
7
c
rr T
.
,
.- iv) The current relationship between two current gain in a transistor is
3-
B) 13 =
1 + a 1? a 1+13
O P
A) 13=
1
a
ot
C) 13 = D) 13 =
0 >,
8
1 ?a 1+a
1
3
c
-
.1
4J b. Draw input and output characteristics of an NPN transistor in common base configuration
0
z and explain.
(10 Marks)
t
;:
cs c. For a Silicon transistor a
d
, = 0.995, emitter current is 10 mA and leakage current 1,? is
O 0.511A. Find lc, IB, J3 and
Icro.
(06 Marks) sa.
-7.
P2
r
?
t, iii) The knee voltage of a silicon diode is
A) 0.3V B) 0.5V C) 0.7V D) none of these
1 of 3
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10ELN15/25
3 a. Choose the correct answ( "
r
te
i) Which of the following factor affects the Q-point stability?
A) I
co
B) coupling capacitor
C) emitter resistor D) bypass capacitor
ii) The inter section of the dc load line with given base current curve is the
A) h-point B) D-point C) Q-point D) none of these
iii) For an emitter follower, the voltage gain is
A) unity B) greater than unity C) less than unity D) zero
iv) The best biasing stability is achieved by using biasing method.
A) fixed B) collector to base C) voltage divider D) none of these
b. Explain the working of collector-to-base bias circuit using an NPN transistor and derive the
equation for IB. (08 Marks)
c. Define stability factor and discuss the factors that cause instability of biasing circuits.
(08 Marks)
(04 Marks)
4 a. Choose the correct answers for the following
i) FET is a controlled device.
A) voltage B) current
ii) PNPN device is an
A) UJT B) SCR
iii) used as a relaxation oscillator.
A) MOSFET B) SCR
iv) The intrinsic standoff ratio of UJT
A) equal to one
C) must be greater than unity
(04 Marks)
C) pulse D) power
C) MOSFET D) MODFET
C) BJT rek ) UJT
B) must be less than unity
D) must be zero
b. Explain the working of two transistor model of an SCR and obtain the expression for the
anode current.
c. Draw the equivalent circuit and VI-characteristic of UJT and explain it.
(08 Marks)
(08 Marks)
(04 Marks)
D) both A and B
B) 2TELC C) 2ic LC D)
2rcLC 2n-4:C
hi) With negative feedback, the bandwidth of an amplifier
A) decreases B) increases C) both A and B D) constant
iv) The magnitude voltage gain at half power frequencies of an RC coupled amplifier is
times maximum voltage gain.
A) 0.707 B) 7.07 C) 10 D) 17.06
b. Draw the frequency response of an RC-coupled amplifier and explain it. Mention its
advantages and disadvantages. (08 Marks)
c. Explain with the help of circuit diagram the working of an RC phase shift oscillator using
transistor.
(06 Marks)
d.
In a transistor colpitts oscillator having tank circuit parameters as ci = 0.001 ILE and
c? = 0.01 pF if L = 51AH, calculate the frequency of oscillations. (02 Marks)
PART ? B
Choose the correct answers for the following :
i) Oscillator uses type of feedback.
A) positive B) negative C) reverse
ii) The frequency of oscillations in an oscillator is given by
A)
1
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10ELN 15/25
6 a. Choose the correct answer; ---
el
(04 Marks)
i) The gain of the voltage follower is
A) zero B) infinite C) negative D) unity
ii) Ideally open loop gain of op-amp is
A) 0 B) 1 C) 00 D) positive
iii) The CMRR is given by
?
A) Ad x A, B) A, /Ad C) Ad /A
c
D) none of these
iv) Maximum rate of change of output voltage with time is called
A) CMRR B) slew rate C) over rate D) none of these
b. List the characteristics of an ideal-op-amp and draw the three input inverting summer circuit
using an op-amp and derive an expression for output voltage. (08 Marks)
c. Draw the basic block diagram of a cathode ray tube and explain its working. (08 Marks)
7 a. Choose the correct answers for the following : (04 Marks)
i) Two's compliant of (1001)
2
is
A) 1001 B) 0010 C) 0111 D) 1010
ii) To represent 35 in binary, number of bits required is
A) 6 B) 5 C) 4 D) 33
iii) Decimal number 37 is represented in BCD by
A) 100111 B) 00111011 C) 00110111 C
I
D) 111100
iv) Over modulation exists when modulation index is
A) 1 B) 0 C) >1
t
D) < 1
b. Explain the need for modulation. (06 Marks)
c. Convert (A3B)16 = ( )10 , and (247.75)10= ( )2.
(04 Marks)
d. i) Perform (FCO2A)16 ? (D052)
1
, using 16's complement.
ii) Subtract (4317.64)8 from (42.345)8 using 8's complement. (06 Marks)
8 a. Choose the correct answers for the following : (04 Marks)
i) The expression for half adder carry with input A and B is given by
A) A + B B) AB C) A B D) none of these
ii) The complement of A + B + 1 is
A) 0 B) A + 1 C) AB + 1 D) 1
iii) ABCD + ABD is equal to
A) ABC B) ABC C) ABD D) ABD
iv) A + (B + C) (A + B) + C is law.
A) associative B) commutative C) distributive D) none of these
b.
c.
Design a full adder circuit and realize, using two half adders.
Simplify the following expressions and implement using only NAND gates :
i) Y = ABC + ABC + ABC + ABC
ii) Y = AB + AC
iii) Y = A + AB .
(08 Marks)
(08 Marks)
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This post was last modified on 01 January 2020