Deck 2: Motor Selection and Applications in Various Industries

Question 1

The size of an excavator is usually expressed in terms of

A)'crowd' motion
B)angle of swing
C)cubic metres
D)travel in metres

Answer 1

cubic metres

Question 2

For blowers which of the following motor is preferred ?

A)D.C.series motor
B)D.C.shunt motor
C)Squirrel cage induction motor
D)Wound rotor induction motor

Answer 2

D.C.shunt motor

Question 3

Belted slip ring induction motor is almost invariably used for

A)water pumps
B)jaw crushers
C)centrifugal blowers
D)none of the above

Answer 3

jaw crushers

Question 4

Which of the following is essentially needed while selecting a motor ?

A)Pulley
B)Starter
C)Foundation pedal
D)Bearings

Question 5

Reluctance motor is a

A)variable torque motor
B)low torque variable speed motor
C)self starting type synchronous motor
D)low noise, slow speed motor

Question 6

method of starting a three phase induction motor needs six terminals.

A)Stardelta
B)Resistance starting
C)Auto-transformer
D)None of the above

Question 7

In method of staging three phase induction motors the starting voltage is not reduced.

A)auto-transformer
B)star-delta
C)slip ring
D)any of the above

Question 8

In jaw crushers a motor has to often start against load.

A)heavy
B)medium
C)normal
D)low

Question 9

For a motor-generator set which of the following motors will be preferred ?

A)Synchronous motor
B)Slip ring induction motor
C)Pole changing induction motor
D)Squirrel cage induction motor

Question 10

Which of the following motors is usually preferred for kiln drives?

A)Cascade controlled A.C.motor
B)Slip ring induction motor
C)Three phase shunt wound com-mutator motor
D)Any of the above

Question 11

Heat control switches are used in

A)transformers
B)cooling ranges
C)three phase induction motors
D)single phase

Question 12

has relatively wider range of speed control.

A)Synchronous motor
B)Ship ring induction motor
C)Squirrel cage induction motor
D)D.C.shunt motor

Question 13

In squirrel cage induction motors which of the following methods of starting cannot be used ?

A)Resistance in rotor circuit
B)Resistance in stator circuit
C)Auto-transformer starting
D)Star-delta starting

Question 14

In which of the following applications the load on motor changes in cyclic order?

A)Electric shovels
B)Cranes
C)Rolling mills
D)All of the above

Question 15

Flame proof motors are used in

A)paper mills
B)steel mills
C)moist atmospheres
D)explosive atmospheres

Question 16

Which of the following machines has heavy fluctuation of load ?

A)Printing machine
B)Punching machine
C)Planer
D)Lathe

Question 17

For derries and winches which of the following drives can be used ?

A)Pole changing squirrel cage motors
B)D.C.motors with Ward-leonard con-trol
C)A.C.slip ring motors with variable resistance
D)Any of the above

Question 18

Battery operated scooter for braking uses

A)plugging
B)mechanical braking
C)regenerative braking
D)rheostatic braking

Question 19

has least range of speed control.

A)Slip ring induction motor
B)Synchronous motor
C)C.shunt motor

Question 20

has the least value of starting torque to full load torque ratio.

A)D.C.shunt motor
B)D.C.series motor
C)Squirrel cage induction motor
D)Slip ring induction motor

Question 21

In case of speed control by injecting e.m.f. in the rotor circuit is possible,

A)d.c.shunt motor
B)schrage motor
C)synchronous motor
D)slip ring induction motor

Question 22

A pony motor is used for the starting which of the following motors ?

A)Squirel cage induction motor
B)Schrage motor
C)Synchronous motor
D)None of the above

Question 23

In the speed can be varied by changing the position of brushes.

A)slip ring motor
B)schrage motor
C)induction motor
D)repulsion motor

Question 24

In which of the following applications variable speed operation is preferred ?

A)Exhaust fan
B)Ceiling fan
C)Refrigerator
D)Water pump

Question 25

Heavy duty cranes are used in

A)ore handling plants
B)steel plants
C)heavy engineering workshops
D)all of the above