Question is ⇒ Which D.C. motor will be preferred for cónstant speed line shafting ?, Options are ⇒ (A) Cumulative compound motor, (B) Differentially compound motor, (C) Shunt motor, (D) Series motor, (E) , Leave your comments or Download question paper.

Question is ⇒ Which D.C. motor will be preferred for cónstant speed line shafting ?, Options are ⇒ (A) Cumulative compound motor, (B) Differentially compound motor, (C) Shunt motor, (D) Series motor, (E) , Leave your comments or Download question paper. Previous question Next question


Q1.	Which D.C. motor will be preferred for cónstant speed line shafting ?
A.	Cumulative compound motor [Wrong Answer]
B.	Differentially compound motor [Wrong Answer]
C.	Shunt motor [Correct Answer]
D.	Series motor [Wrong Answer]
View Answer 8 -5 Explanation:- Answer : C Discuss it below : !! OOPS Login [Click here] is required to post your answer/result Help other students, write article, leave your comments

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Also Read Similar Questions Below :

⇒ The speed regulation of a D.C. motor is

lowest speed

highest speed

highest speed - lowest speed

average speed

no-load speed - full-load speed

full-load speed

no-load speed - full-load speed

no-load speed

⇒ VVhat is the effect produced by the electric current in an electric motor ?
Heating effect only
Magnetic effect only
Heating as well as magnetic effect
Heating as well as chemical effect

⇒ When two D.C. series motors are connected in parallel, the resultant speed is
more than the normal speed
loss than the normal speed
normal speed
zero

⇒ By looking at which part of the motor, it can be easily confirmed that a particular motor is D.C. motor?
Frame
Shaft
Commutator
Stator

⇒ Which of the following steps is likely to result in reduction of hysteresis loss in a D.C. generator ?
Providing laminations in armature core
Providing laminations in stator
Using non-magnetic material for frame
Using material of low hysteresis coefficient for armature core material

⇒ Regenerative braking on shunt motors is used when
the load is variable
the load is constantly decreasing
the load acts as a braking force
the load has overhauling characteristics.

⇒ Hopkinson's test on D.C. machines is conducted at
no-load
part load
full-load
overload

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

⇒ One D.C. motor drives another D.C. motor. The second D.C. motor when excited and driven
runs as a generator
does not run as a generator
also runs as a motor
comes to stop after sometime

⇒ The main disadvantage of Hopkinson's test for finding efficiency of the shunt D.C. motors is that it
needs one motor and one generator
requires two identical shunt machines
requires full-load power
ignores any change in iron loss

⇒ 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

⇒ A direct on line starter is used for starting motors
up to 5 H.P.
up to 10 H.P.
up to 15 H.P.
up to 20 H.P.

⇒ If the supply voltage for a D.C. motor is increased, which of the following will decrease ?
Starting torque
Operating speed
Full-load current
All of the above

⇒ D.C. generators are normally designed for maximum efficiency around
full-load
rated r.p.m.
rated voltage
all of the above

⇒ In Ward Leonard method of speed control of a D.C. motor, change in speed of motor is obtained by the
change in armature voltage of D.C. motor
change in the field excitation of the D.C. motor
change in armature current of D.C. motor
change in supply voltage

⇒ 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

⇒ The purpose of retardation test on D.C. shunt machines is to find out
stray losses
eddy current losses
field copper losses
windage losses

⇒ The speed of a D.C. shunt motor is required to be more than full load speed. This is possible by
reducing the field current
decreasing the armature current
increasing the armature current
increasing the excitation current

⇒ In a manual shunt motor starter
over load relay is connected in series and no volt relay in parallel with the load
over load relay is connected in parallel and no volt relay in series with the load
over load relay and no volt relay are both connected in series with the load
over load relay and no volt relay are both connected in parallel with the load

⇒ If t be the thickness of the laminations, then eddy current loss in a generator. will vary as
¹/_t
¹/_t²
t
t²

⇒ Which of the following, in a D.C. motor, can sustain the maximum temperature rise ?
Commutator
Armature windings
Slip rings
Field windings

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

⇒ If T_a be the torque and Ia the armature current for a D.C. motor, then which of the following relation is valid before saturation ?
T_a ∝ I_a
T_a ∝ I/I_a
T_a ∝ I_a²
T_a ∝ ^I/_{I_a²}

⇒ Torque developed by a D.C. motor depends upon
active length of the conductor
current flow through the conductors
number of conductors
radius of armature

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

⇒ Which method of braking is generally used in elevators ?
Plugging
Regenerative braking
Rheostatic braking
None of the above

⇒ Between Field's test and Hopkinson's test the main common thing is that both
use negligible power
are regenerative tests
need two similar mechanicallycoupled motors
need two electrically coupled series motors

⇒ In case of conductively compensated D.C. series motors, the compensating winding is provided
as separately wound unit
in parallel with armature winding
in series with armature winding
in parallel with field winding

⇒ In a D.C. series motor, if the armature current is reduced by 50%, the torque of the motor will be equal to
100% of the previous value
50% of the previous value
25% of the previous value
10% of the previous value

⇒ Which D.C. motor is generally preferred for cranes and hoists ?
Series motor
Shunt motor
Cumulatively compounded motor
Differentially compounded motor