Scribd
Upload
54 views2 pages

Electrical Engineering Exam Key

The document appears to be a revised key for an examination on electrical engineering. It provides answers to multiple choice and numerical questions related to topics like circuit analysis, DC machines, transformers, synchronous motors, and single-phase induction motors. Some answers have been deleted. The key gives the correct answer for questions about use of mesh analysis, inductance in a circuit, damping in a galvanometer, capacitance value for a non-inductive pressure coil circuit, minimum commutator bars for an armature winding, torque-speed characteristics of a DC motor, factors governing the lower speed limit in a Ward-Leonard system, operation of a shunt machine in a Swinburne test, voltage regulation of a transformer

Uploaded by

Harish Palla
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
54 views2 pages

Electrical Engineering Exam Key

The document appears to be a revised key for an examination on electrical engineering. It provides answers to multiple choice and numerical questions related to topics like circuit analysis, DC machines, transformers, synchronous motors, and single-phase induction motors. Some answers have been deleted. The key gives the correct answer for questions about use of mesh analysis, inductance in a circuit, damping in a galvanometer, capacitance value for a non-inductive pressure coil circuit, minimum commutator bars for an armature winding, torque-speed characteristics of a DC motor, factors governing the lower speed limit in a Ward-Leonard system, operation of a shunt machine in a Swinburne test, voltage regulation of a transformer

Uploaded by

Harish Palla
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
You are on page 1/ 2

ASSISTANT EXECUTIVE ENGINEERS (Notification No.

09/2018)
Electrical Engineering (Paper-II)

REVISED KEY

8.Use mesh analysis to find the current in the given circuit


DELETED

19. In the circuit of Fig. , the magnitudes of VL and VC are twice that of VR. The inductance
of the coil is
DELETED

28. If the damping in an d’Arsonval galvanometer is only due to electromagnetic effects,


the resistance required for critical damping is

DELETED

31.A capacitor is connected across a portion of a resistance of the multiplier in order to make
the presser coil circuit non-inductive. The value of this resistance is ‘r’ while the total resistance
and inductance of pressure circuit are respectively Rp and L. Then the capacitance C is

0.41 L/r2

57. The armature of a DC generator has a 2-layer lap-winding housed in 72 slots with six
conductors per slot. What is the minimum number of commutator bars required for the
armature?
72

71. A DC motor develops a torque of 200 N-m at 25 rps. At 20 rps it will develop a torque of ---
---------N-m
Both 200 and 250

76. The lower limit of speed in a Ward-Leonard method of speed control is governed by

1. Losses in both the machines


2. Residual magnetism of the generator
3. Armature circuit resistance of both the machines

4. Speed of the generator-prime mover

From these, the correct answer is

2 only
79. In Swinburne’s method of testing Dc machines, the shunt machine is run as a

Motor at no load at no rated speed and rated voltage

90. The voltage regulation of a transformer at full-load and 0.8 pf lagging is 2.5%. The voltage
regulation at full load 0.8 pf leading will be

DELETED

134. Which the following method is used to start a synchronous motor?

DELETED

135. A salient-pole synchronous motor runs under steady-state conditions at no load with
armature current ia . If the field circuit gets open-circuited, then
it runs at a slower speed as an induction motor and and ia increases

142. In a 1-phase induction motor, according to the double-revolving field theory,


A. Forward mmf Ff and backward mmf Fb are equal at standstill
B. Ff and Fb are equal at all rotor speeds

C. Forward flux f and backward flux b are equal at all rotor speeds

D. f and b are equal at standstill

From above, the correct is


A, D

143. A single-phase, 6-pole, 50 Hz induction motor has rotor resistance of 19 ohms and rotor
self-reactance of 20 ohms. In addition to zero speed, the motor torque would be zero at a
speed of
1000 rpm

You might also like