JNTU Kakinada B-Tech 2-1 R1621041 ELECTRONIC DEVICES AND CIRCUITS R16 May 2018 Question Paper

Code No: R1621041

II B. Tech I Semester Supplementary Examinations, May – 2018
ELECTRONIC DEVICES AND CIRCUITS (Com to ECE, EIE and ECC)Time: 3 hours Max. Marks: 70
Note: 1. Question Paper consists of two parts (Part-A and Part-B) 2. Answer ALL the question in Part-A
3. Answer any FOUR Questions from Part-B
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PART ?A
1. a)Explain the terms mobility and conductivity of a Semiconductors in detail (2M)
b) Define Diffusion capacitance and Transition capacitance of a PN junction
diode (3M)
c)What is the need for filters in power supplies (2M)
d)What are the different configurations of BJT (2M)
e)Define biasing and explain the Need for biasing (2M)
f)Explain the Generalized analysis of small signal model in detail (3M)
PART ?B
2. a) Define Hall effect and Derive Hall coefficient expression along with
applications of Hall effect (7M)
b) In a P-type semiconductor the resistivity of the bar is 220X10
3
?, width is
2mm, Magnetic flux is 0.1 wb/m
2
, I=5? amps, V
H
=28m volts Find the Hole
mobility of a Semiconductor Bar. (7M)
3. a) The reverse saturation current I
o
in a germanium diode is 6?A. Calculate the
current flowing through the diode when the applied forward biase voltages are
0.2,0.3 and 0.4 V at room temperature. (10M)
b) Describe the principal of operation of an LCD (4M)
4. a) A 230V, 50 z voltage is applied to the primary of 5:1 step down center-tap
transformer used in a full-wave rectifier having a load of 900?. If the diode
resistance and secondary coil resistance together has a resistance 100? ,
determine (i)DC voltage across the load (ii) DC current flowing through load (iii)DC owe delivered to the load (iv) PIV across diode (v) ripple voltage and
its frequency. (7M)
b) Derive the expression for a ripple factor in a full-wave rectifier with resistive
load in detail (7M)
5. a) Draw the circuit diagram of an NPN junction transistor CE configuration and
describe the static input and output characteristics. Also, Define active,
saturation and cutoff regions and saturation resistance of a CE transistor (7M)
b)Determine I
C
, I
E
and a for a transistor circuit having IB=15?A and ?=150. (7M)
1 of 2
SET – 1
R16

Code No: R1621041

II B. Tech I Semester Supplementary Examinations, May – 2018
ELECTRONIC DEVICES AND CIRCUITS (Com to ECE, EIE and ECC)Time: 3 hours Max. Marks: 70
Note: 1. Question Paper consists of two parts (Part-A and Part-B) 2. Answer ALL the question in Part-A
3. Answer any FOUR Questions from Part-B
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PART ?A
1. a)Explain the terms mobility and conductivity of a Semiconductors in detail (2M)
b) Define Diffusion capacitance and Transition capacitance of a PN junction
diode (3M)
c)What is the need for filters in power supplies (2M)
d)What are the different configurations of BJT (2M)
e)Define biasing and explain the Need for biasing (2M)
f)Explain the Generalized analysis of small signal model in detail (3M)
PART ?B
2. a) Define Hall effect and Derive Hall coefficient expression along with
applications of Hall effect (7M)
b) In a P-type semiconductor the resistivity of the bar is 220X10
3
?, width is
2mm, Magnetic flux is 0.1 wb/m
2
, I=5? amps, V
H
=28m volts Find the Hole
mobility of a Semiconductor Bar. (7M)
3. a) The reverse saturation current I
o
in a germanium diode is 6?A. Calculate the
current flowing through the diode when the applied forward biase voltages are
0.2,0.3 and 0.4 V at room temperature. (10M)
b) Describe the principal of operation of an LCD (4M)
4. a) A 230V, 50 z voltage is applied to the primary of 5:1 step down center-tap
transformer used in a full-wave rectifier having a load of 900?. If the diode
resistance and secondary coil resistance together has a resistance 100? ,
determine (i)DC voltage across the load (ii) DC current flowing through load (iii)DC owe delivered to the load (iv) PIV across diode (v) ripple voltage and
its frequency. (7M)
b) Derive the expression for a ripple factor in a full-wave rectifier with resistive
load in detail (7M)
5. a) Draw the circuit diagram of an NPN junction transistor CE configuration and
describe the static input and output characteristics. Also, Define active,
saturation and cutoff regions and saturation resistance of a CE transistor (7M)
b)Determine I
C
, I
E
and a for a transistor circuit having IB=15?A and ?=150. (7M)
1 of 2
SET – 1
R16

Code No: R1621041

6. a) A transistor amplifier V
cc
=12V, R
1
=8K?, R
2
=4K?, R
e
=1K? and
R
l
=1.5K?.Assume V
be
=0.7V Determine the operating point and draw the DC
and AC load line. (7M)
b) Explain the collector to base bias method along with circuit diagram and derive
the stability factor for it (7M)
7. a) In the CE amplifier calculate the mid frequency voltage gain and lower 3-dB
point. The transistor has h-parameters h
fe
=400 and h
ie
=10k?, the circuit details
are Rs=600?, R
L
=5K?, Re=1K?, Vcc=12V R1=15K?,R2=2.2.K? and
Ce=50?F. (7M)
b)Draw the circuit diagram of CB amplifier and explain its operation in detail (7M)

2 of 2
SET – 1
R16