51.

52.

53.

54

55.

56.

57.

58.

59.

Why the double cage rotor of a 3-phase squirrel cage induction motor is short circuited ?
(4) To reduce the slip (B) एणा quick starting
(C) For pulling more load (D) 1௦ maintain good torque

Why the rotor bars of a 3 phase squirrel cage induction motor are mounted in a slightly
skewed position ?

(4) To avoid magnetic locking (B) To maintain cons.... See more

‘Compound generator
B:-Shunt generator
Series generator
D:-Differentially compound generator
Correct Answer:- Option-8
Question66:-For high starting torque which type of DC motors used ?
॥ ‏وها‎ motor
B:-Shunt motor

CCumulative compound motor

Differential compound motor
Correct Answer:- Option-A

Question67:-The maximum power output for DC motor is at

Eb = 098/2
Correct Answer: Option-8

Question68:-In ward.... See more

24.

28.

26.

27.

28.

29,

30.

81,

Which type of transformer winding has ‏مص‎ ohmic resistance and no magnetic leakage
resulting in no losses?

(A) Distribution transformer 18) Power transformer

(©) Ideal Transformer (D) Instrument transformer

Which of the following speed is called synchronous speed in a 3 phase induction motor?
(A) Speed of the rotating magnetic field - (B) Speed of the.... See more

ഇ! 0472017

19.

20.

21.

22.

23.

24.

25.

26.

27.

Collector current, ಗ of BJT =
A) I का, 8( -1, 0( ‏و2-۔ے]‎ 0) ௩2

Capacitive reactance is
A) Directly proportional to frequency B) Directly proportional to capacitance
C) Independent on frequency D) Inversely proportional to frequency

Current gain of common base amplifier is
A) Always less than 1 B) Always greate.... See more

68. Universal motor is :

(ಗಿ) DC series motor (B) AC series motor

(6) Synchronous motor (D) Induction motor

69, Crawling phenomenon is associated with :

(^) Universal motor (B) Synchronous motor

(C) Induction motor (D) Alternator

70. Select the incorrect statement :

(ക Synchronous motor runs only at synchronous speed
(B) Under excited synchronous motor is also known as synchronous condenser
)© अष्ट] phase induc.... See more

27, णः द tansformer the all day efficiency primarily depends on :
(ക) the amount of load (B) duration of load
(C) its copper loss (D) both (A) and (B)
28. If a D.C. motor is connected across the A.C. supply it will ;
(A) run at normal speed
(8) mnot run
(C) ரமா மண ‏٤٭د‎
‎(D) ण्ठा वेप to heat produced in the field winding by eddy currents
29. D.C. motor would be preferred for conveyors :
(A) Series motor (8) S.... See more

6.

62,

63.

64.

65,

66,

67,

Which one of the following method is not suited for starting a squirrel cage induction motor ?
(ಹ) DOL starting (8) Auto transformer starting
(ಲ) Star Delta starting (D) Rotor Resistance starting

What happens if single phasing occurs when a 3 phase induction motor is running at நத
full load ?

(^) Motor stops

(B) Motor stalls

(ಲ) Motor keeps running a.... See more

93.

94.

95.

96.

97.

98.

If a motor cycle is found driven by a juvenile with the knowledge of the

guardian / owner, பட

(A) The guardian / owner shall be punishable with imprisonment for a term which may
be extended to three years

(B) The guardian / owner shall be liable to remit the fine of Rs. 25000/-

(C) The registration certificate of the vehicle shall be suspended temporarily

(D) All of .... See more

53.

54.

55.

56.

57.

58.

59.

075/23

As the load on the transformer is increased, the core losses

A) Decrease slightly

B) Increase slightly

C) Remain constant

D) May decrease or increase slightly depending upon the nature of load

‘Crawling’ in an induction motor is due to

A) Space harmonics produced by winding currents
B) Insufficient starting torque

C) Sli.... See more

135/2015

Maximum : 100 marks

Time : 1 hour and 15 minutes

In a slip ring induction motor slip rings are connected to the :
(4) ஸு (B) Stator
(C) Exciting field (D) Centrifugal switch

Which motor is used for electric traction?
(4) DC compound motor (B) ദേ phase induction motor
(C) DC series motor (D) DC shunt motor

How many slip rings are there in a slip ring induction motor?
@ 2 © 3
© 4 യ 6

The stator windi.... See more

35.

37.

38.

39.

40.

41.

A 6 pole induction motor is connected to a 50 C/S supply. It 15 running at 970 rev/min.
What is the percentage slip ?

(A) 3% ൫ 4% ര 5% (2) 6%

When motor is fed with reduced voltage, the motor draws excess current to drive the load.
When a motor is fed with an over vollage, how much current will the motor draw ?

(A) Low current (ए) Normal current (C) Excess current (D) Zero curre.... See more

86.

87,

88,

89.

90.

91,

92,

93.

Zero power factor method is used to find of an alternators.
(ക) Power factor (8) Synchronous impedance
(C) Efficiency (D) Voltage regulation

A 10 Q resistor, 0.1 H inductor and 150 uF capacitor are connected in series and give a
200 V, 50 Hz ac supply. Find the power factor of the circuit.

^) 0.6 ® 0.5
© 7 യ 09

At the time of 3 phase power measu.... See more

48.

49.

50.

51.

52.

53.

54.

Speed of a DC motor

(A) Directly proportional to flux

(B) Directly proportional of back emf

(C) Inversely proportional to supply voltage

(D) Can't change by increasing supply voltage

Shaft torque in DC motor is

(A) less than armature torque
(B) greater than armature torque
(C) equal to armature torque

(D) square of armature torque
<.... See more

149/2017 O ‏۷ل‎

79

80.

81.

82.

83.

84.

88.

88.

. The type of motor used in ceiling fan is
A) Split phase B) Capacitor start
©) Capacitor start capacitor run D) Permanent capacitor

Which one of the following motor will have lowest starting torque ?
A) Universal motor 18) Shaded pole motor

©) Capacitor start capacitor run motor D) Repulsion induction motor

When the speed .... See more

44.

45,

46,

47.

48.

49.

=

51.

The efficiency of a transformer will be maximum when :
(8) Iron losses are equal to copper losses
(B) Iron losses are more than copper losses
(C) 70 losses are less than copper losses
(D) None of the above

Commonly used a.c. Motor in industrial area :
(ക) Slipring induction motor (B) Squirrel cage induction motor

(0) Synchronous motor (D) Universal motorSee more

58.

59.

60.

"61.

62.

68.

64.

65.

The current drawn by a 240 DC motor of armature resistance 0.5 ohm and back emf of 220
will be :

4) ۸ ‏رو‎ 508
© 104 യു 40%

For wide and very sensitive speed control, the usual method is :
(4) Field control (0) Armature control
(C) Voltage control (D) Ward-Leonard control

The speed of a DC motor can be controlled by varying :
(^) the .... See more

77,

78.

79.

80,

81.

82,

83.

85.

Rotor rheostatic method of speed control is used for :
(ക) slip ning induction motor (B) squirrel cage induction motor
)6 DC series motor (D) DC shunt motor

What is meant by plugging in the case of a 3-phase induction motor ?
(A) locking of rotor due to harmonics

(8) interchanging two supply phases for quick stopping

(C) starting the motor with direct o.... See more

46.

47.

48.

49,

50,

51,

52,

53,

Advantage of Hydro electric power station is 8
(ಹಿ) Low cost (8) Free from pollution
(ಲ) No fuel transportation problem (D) All of the above

Which of the following system electric power maybe transmitted ?
(^) Overhead system

(8) Underground system

(9) Overhead and underground system

(D) None of these

The fuel used in nuclear gener.... See more

78.

79.

80.

81,

82,

83,

84,

85,

Brass contains Copper and .
(A) Tin (B) Lead
(C) Zinc (D) Nickel

The earth resistance of any earthing should not be more than
(ಹ) 1ohm (B) 5ohm
© 10൨ ©) 3ohm

The minimum size of earth conductor used ‏طط‎ a domestic installation is
(A) 6 (3) 12SWG
(ಲ) 168%6 (D) 6

In an ac circuit 3 €2 resistor is connected in series with a 4 Q) .... See more

=

68. Which of the following statements is/are true regarding mechanical characteristic of a
de shunt motor ?
i. Itis the graph between torque and speed of motor.
॥. Itis the graph between armature current and armature torque.
iii. The shape of the characteristic is linear.
iv. The shape of the characteristics is hyperbolic.
A) Only i and iv B) Only ii and iii
C) Only i and iii D) Only ii and iv

. During the no load test on a 200 ۷, DC shunt motor.... See more

075/23

60.

61.

62.

63.

64.

65.

66.

For a given stepper motor, which of the following torque has the highest numerical value ?
A) Pullin torque B) Pullout torque C) Holdingtorque D) Detent torque

The interpoles in DC machines have a tapering shape in order to

A) reduce the overall weight

) increase the acceleration of commutation

) reduce the saturation in the interpoles

) econ.... See more

81.

82.

94.

85,

56.

87.

88,

A 4 pole simplex lap-wound armature having 48 slots, each slot has 4 conductors and 6800
conductor is having resistance of 0.1 ohms. What will be the total armature resistance?

(५) 0.48 0811 (2) 1.2chms

(€) 1.92 ochms (D) 4.8 chms

Speed of DC shunt motor has to be controlled through the field. Which starter is most
suitable in this case?

{A) 4 point starter (.... See more

23,

24.

25.

26.

21.

28.

29.

30.

A 3 = phage, 400 volts, 50Hz, 100 KW, 4 pole squirrel cage induction motor with a rated slip
of 2% will have a rotor speed വ്‌: .

(ക) 1500 rpm (B) 1470 rpm
(C) 1530 rpm ALY (D) 1570 rpm

A 3 — phase, 400 velts, 50 Hz, 100 KW, 4 pole squirrel cage induction motor with a rated slip
of 2% will have a rotor speed of :

(^) 1500 rpm (B) 1470 rpm
)6.... See more

54,

55,

56,

57.

58,

59,

60,

61,

An Auto transformer which has only one winding may be used as 3
(ಹ) Step-up transformer

(B) Step-down transformer

(9) Step-up and Step-down transformer

(D) None of these

The unit of solid angle is a ‏٦‎
‎(^) Lumen (8) ಟ್ರ (C) Steradian (D) Candela

Full form of MCCB is .

(ಹಿ) Moulded Case Circuit Breaker

(.... See more

42.

43.

44.

45.

46.

47.

48.

Armature of a DC machine is made of
(A) conducting material (B) insulating material

(C) non-ferrous material (D) silicon steel

Which DC motor has got maximum self loading property?
(A) shunt motor

(B) series motor

(C) differentially compounded motor

(D) cumulatively compounded motor

When a DC series motor is connected to an AC supply, then
(.... See more