Download AKTU (Dr. A.P.J. Abdul Kalam Technical University (AKTU), formerly Uttar Pradesh Technical University (UPTU)) B-Tech 2nd Semester (Second Semester) 2018-2019 KEE201 Electrical Engineering Question Paper
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KEE201
Page 1 of 2
Printed Pages: 02 Sub Code:KEE201
Paper Id: 120262 Roll No.
B TECH
(SEM II) THEORY EXAMINATION 2018-19
ELECTRICAL ENGINEERING
Time: 3 Hours Total Marks: 100
Note: 1. Attempt all Sections. If you require any missing data, choose suitably.
SECTION A
1. Attempt all questions in brief. 2 x 10 = 20 CO
a. Define the purpose of Earthing the electrical appliances 5
b. What are the various three phase transformer connections? Name them. 3
c. Explain why transformer cannot be operated on DC. 3
d. What is difference between primary and secondary batteries? 5
e. Define active and passive elements. 1
f. Three resistances each of 20?, 30? & 50? are connected in delta. Calculate
corresponding resistances in equivalent star connection.
1
g. What is phase angle difference between the voltage and current phasors in
purely capacitive circuits?
2
h. A 3-phase, 440V, induction motor is wound for 4 poles and is supplied from
50Hz supply system. Calculate the speed of the motor when slip is 5%.
4
i. Write condition for series resonance. 2
j. Write applications of synchronous motor.
4
SECTION B
2. Attempt any three of the following: Marks CO
a. Derive the relationship in delta and star connected systems?
10 1
b. Derive the expression for the average power in a single phase purely
Resistive circuit. Also draw the phasor diagram and waveform
diagram for this circuit.
10 2
c. An 1100/110V, 22KVA, 1? transformer has primary resistance and
reactance 4? and 6? respectively. The secondary resistance
and reactance are 0.04? and 0.065? respectively. Calculate
(i) Equivalent resistance and reactance of secondary referred to
primary.
(ii) Total resistance & reactance referred to primary.
(iii) Equivalent resistance and reactance of primary referred to
secondary.
(iv) Total copper loss
10 3
d. Derive and explain torque-slip Characteristics of 3-phase Induction
motor.
10 4
e. Explain (i) MCB (ii) ELCB (iii) MCCB 10 5
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| 08-May-2019 08:58:39 | 45.115.62.2
FirstRanker.com | 08-May-2019 08:58:39 | 45.115.62.2
KEE201
Page 1 of 2
Printed Pages: 02 Sub Code:KEE201
Paper Id: 120262 Roll No.
B TECH
(SEM II) THEORY EXAMINATION 2018-19
ELECTRICAL ENGINEERING
Time: 3 Hours Total Marks: 100
Note: 1. Attempt all Sections. If you require any missing data, choose suitably.
SECTION A
1. Attempt all questions in brief. 2 x 10 = 20 CO
a. Define the purpose of Earthing the electrical appliances 5
b. What are the various three phase transformer connections? Name them. 3
c. Explain why transformer cannot be operated on DC. 3
d. What is difference between primary and secondary batteries? 5
e. Define active and passive elements. 1
f. Three resistances each of 20?, 30? & 50? are connected in delta. Calculate
corresponding resistances in equivalent star connection.
1
g. What is phase angle difference between the voltage and current phasors in
purely capacitive circuits?
2
h. A 3-phase, 440V, induction motor is wound for 4 poles and is supplied from
50Hz supply system. Calculate the speed of the motor when slip is 5%.
4
i. Write condition for series resonance. 2
j. Write applications of synchronous motor.
4
SECTION B
2. Attempt any three of the following: Marks CO
a. Derive the relationship in delta and star connected systems?
10 1
b. Derive the expression for the average power in a single phase purely
Resistive circuit. Also draw the phasor diagram and waveform
diagram for this circuit.
10 2
c. An 1100/110V, 22KVA, 1? transformer has primary resistance and
reactance 4? and 6? respectively. The secondary resistance
and reactance are 0.04? and 0.065? respectively. Calculate
(i) Equivalent resistance and reactance of secondary referred to
primary.
(ii) Total resistance & reactance referred to primary.
(iii) Equivalent resistance and reactance of primary referred to
secondary.
(iv) Total copper loss
10 3
d. Derive and explain torque-slip Characteristics of 3-phase Induction
motor.
10 4
e. Explain (i) MCB (ii) ELCB (iii) MCCB 10 5
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| 08-May-2019 08:58:39 | 45.115.62.2
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KEE201
Page 2 of 2
SECTION C
3. Attempt any one part of the following: Marks CO
a. Determine current through 2? resistor using Thevenin theorem. 10 1
b. Determine current through 8? resistor and power in the 4 ? resistor in
the Network shown in Fig. Using Superposition theorem.
10 1
4. Attempt any one part of the following: Marks CO
a. Why is a single phase induction motor is not self starting. Also explain
the various starting methods.
10 4
b. A 250V dc shunt motor takes 41A at full load. Resistances of motor
armature and shunt field winding are 0.1? and 250? respectively.
Find the back emf on full load. What will be generated emf, if working
as generator and supplying 41A to a load at terminal voltage of 250V?
10 4
5. Attempt any one part of the following: Marks CO
a. Derive half power frequencies, bandwidth and quality factor for series
resonance occurring in a series R-L-C circuit.
10 2
b. A balanced delta connected load of 12+j9 ohm is connected to 3 phase
400 V supply. Find (i) Line current (ii) power factor (iii) power drawn
(iv) reactive volt amp (v) total volt amp
10 2
6. Attempt any one part of the following: Marks CO
a. What is an Auto Transformer? What are the advantages and
disadvantages of using an Auto Transformer? Explain (without
derivation) how the efficiency varies when a normal two winding
transformer is converted into an Auto Transformer.
10 3
b. A transformer is rated at 100kVA. At full load its copper loss is
1200Watts and iron losses are 960W. Calculate: (i) Efficiency at full
load, unity pf (ii) Efficiency at half load, 0.8 pf lagging. (iii)
Efficiency at 75% full load, 0.7 pf lagging (iv) The load KVA at
which maximum efficiency occurs (v) The maximum efficiency at
0.85 pf lagging
10 3
7. Attempt any one part of the following: Marks CO
a. Describe electrical characteristics of lead acid battery. 10 5
b. Explain the construction, rating and specific applications of at least two
types of Wires and Cables used in electrical engineering.
10 5
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This post was last modified on 29 January 2020