Question is ⇒ Which of the following methods is most effective in finding out the no load losses in a large D.C. shunt motor ?, Options are ⇒ (A) Field's test, (B) Ward-Leonard test, (C) Block rotor test, (D) Swinburne's test, (E) Hopkinson's test, Leave your comments or Download question paper.

Question is ⇒ Which of the following methods is most effective in finding out the no load losses in a large D.C. shunt motor ?, Options are ⇒ (A) Field's test, (B) Ward-Leonard test, (C) Block rotor test, (D) Swinburne's test, (E) Hopkinson's test, Leave your comments or Download question paper. Previous question Next question


Q1.	Which of the following methods is most effective in finding out the no load losses in a large D.C. shunt motor ?
A.	Field's test [Wrong Answer]
B.	Ward-Leonard test [Wrong Answer]
C.	Block rotor test [Wrong Answer]
D.	Swinburne's test [Correct Answer]
E.	Hopkinson's test [Wrong Answer]
View Answer 8 -3 Explanation:- Answer : D Discuss it below : !! OOPS Login [Click here] is required to post your answer/result Help other students, write article, leave your comments

Previous question Next question

Also Read Similar Questions Below :

⇒ A series motor is started without load. The effect is that
the back e.m.f. decreases
the torque increases rapidly
the speed increases rapidly
the current drawn increases rapidly

⇒ A series motor is' best suited for driving
machine tools
cranes and hoists
shear and punches
none of the above

⇒ Small D.C. motors up to 5 H.P. usually have
2 poles
4 poles
6 poles
8 poles

⇒ Why are the D.C. motors preferred for traction applications ?
Torque and speed are inversely proportional to armature current
Torque is proportional to armature current
Torque is proportional to square root of armature current
The speed is inversely proportional to the torque and the torque is proportional to square of armature current

⇒ When the electric train is moving down a hill the D.C. motor act as
D.C. series generator
D.C. shunt generator
D.C. shunt motor
D.C. series motor

⇒ Speed control of a cumulatively compounded D.C. motor can be effected through change of
field resistance
armature resistance
armature voltage
any of the above

⇒ A D.C. series motor, as compared to shunt and compound motors, has the highest torque at the start because of its comparatively
stronger series field
lower armature resistance
large armature current
fewer series turns

⇒ Which D.C. motor has got maximum self loading property?
Series motor
Shunt motor
Cumulatively compounded motor
Differentially compotinded motor

⇒ Which of the following can be used to control the speed of a D.C. motor ?
Thermistor
Thyristor
Thyratron
Transistor

⇒ If the field of a D.C. shunt motor gets opened while motor is running
the speed of motor will be reduced
the armature current will reduce
the motor will attain dangerously high speed
the motor will continue to run at constant speed

⇒ In D.C. machines the residual magnetism is of the order of
2 to 3 per cent
10 to 15 per cent -
20 to 25 per cent
50 to 75 per cent

⇒ For starting a D.C. motor a starter is required because
it limits the speed of the motor
it limits the starting current to a safe value
it starts the motor
none of the above

⇒ Which of the following statements is correct, in case of a D.C. series motor ?
It should be directly connected to the load
It may run away if its field becomes open
It is a constant speed motor
It cannot be used where high starting torque is required

⇒ The condition for maximum power in case of D.C. motor is
back e.m.f. = 2 x supply voltage
back e.m.f. = 1/2 x supply voltage
supply voltage = 1/2 x back e.m.f.
supply voltage = back e.m.f.

⇒ Field winding of a D.C. series motor is usually provided with thick wire
to provide large flux
to reduce the use of insulating materials
as it carries large load current
in order to reduce eddy current

⇒ Which of the following motor has high starting torque ?
Synchronous motor
A.C. series motor
D.C. series motor
Induction motor

⇒ The ratio of starting torque to fullload torque is least in case of
series motors
shunt motors
compound motors
none of the above

⇒ In electric motors carbon brushes are used to
provide a path for flow of current
prevent sparking during commutation
prevent overheating of armature windings
brush off carbon deposits on the commutator

⇒ A D.C. series motor is that which
has its field winding consisting of thick wire and less turns
has a poor torque
can be started easily without load
has almost constant speed

⇒ Speed control by Ward Leonard method gives uniform speed variation
in one direction
in both directions
below normal speed only
above normal speed only

⇒ Which of the following motor is preferred for operation in highly explosive atmosphere ?
Series motor
Shunt motor
Air motor
Battery operated motor

⇒ A face plate starter is employed for starting
induction motor
universal motor
synchronous motor
d.c. series motor

⇒ The total losses in a well designed D.C. generator of 10 kW will be nearly
100 W
500 W
1000 W
1500 W

⇒ Regenerative method of braking is based on that
back e.m.f. is less than the applied voltage
back e.m.f. is equal to the applied voltage
back e.m.f. of rotor is more than the applied voltage
none of the above

⇒ If B_max is the maximum flux density, then eddy cu rrent loss will vary as
B_max
(B_max)²
(B_max)^1.2
(B_max)^2.4

⇒ Compensating winding in a D.C. machine is placed
on yoke in the pole faces
on yoke in the interpolar gap
on armature
none of the above

⇒ In a D.C. generator all of the following could be the effects of iron losses except
Loss of efficiency
Excessive heating of core
Increase in terminal voltage
Rise in temperature of ventilating air

⇒ If the speed of a D.C. shunt motor is increased, the back e.m.f. of the motor will
increase
decrease
remain same
become zero

⇒ What will happen if supply terminals of D.C. shunt motor are interchanged ?
The direction of rotation will reverse
Motor will stop
Motor will run at speed lower than the normal speed in the same direction
Motor will run at its normal speed in the same direction as it was running

⇒ If conditions for maximum power for a D.C. motor are established, the efficiency of the motor will be
less than 50%
60 to 70%
80 to 90%
1