Deck 10: Motor and Power Systems

Question 1

The .......motors, because of their inherent characteristics, are best suited for the rolling mills

A)dc motors
B)slip ring induction motors
C)squirrel cage induction motors
D)single phase motors.

Answer 1

dc motors

Question 2

In case of kiln drives

A)starting torque is almost zero
B)starting torque and running torque are nearly equal
C)starting torque is more than double of the running torque.
D)all of the above

Answer 2

starting torque is more than double of the running torque.

Question 3

Belt conveyors offer

A)zero starting torque
B)low starting torque
C)medium starting torque
D)high starting torque.

Answer 3

high starting torque.

Question 4

In case belt conveyors

A)squirrel cage motors with direct-on-line starters are used
B)single phase induction motors are used
C)dc shunt motors are used
D)induction motors with star-delta starters are used.

Question 5

Which of the following motor is preferred for blowers ?

A)wound rotor induction motor
B)squirrel cage induction motor
C)dc shunt motor
D)dc series motor.

Question 6

Centrifugal pumps are usually driven by

A)dc shunt motors
B)dc series motors
C)squirrel cage induction motors

Question 7

In case of centrifugal pumps the starting torque is generally

A)double the running torque
B)slightly more than running torque
C)same as running torque
D)less than running torque.

Question 8

In a centrifugal pump if the liquid to be pumped has density twice that of water, then the horse power required (as compared to that while pumping water) will be

A)half
B)same
C)double
D)four times.

Question 9

Wound rotor and squirrel-cage motors with high slip which develop maximum torque at stand still are used for

A)machine tools
B)presses and punches
C)elevators
D)all of the above.

Question 10

Belted slip ring induction motor is almost invariably used for

A)centrifugal blowers
B)jaw crushers
C)water pumps
D)screw pumps.

Question 11

A solar cell converts light energy into __________

A)Electrical energy
B)Thermal energy
C)Sound energy
D)Heat energy

Question 12

There are three types of the solar cells.

A)True
B)False
C)none
D)all of the above

Question 13

The output power of the centrifugal pump is proportional to the _________ of the speed.

A)Square
B)Cube
C)Square-root
D)Cube-root

Question 14

There are four types of Water pumps.

A)True
B)False
C)none
D)all of the above

Question 15

The output of the Solar panel is DC.

A)True
B)False
C)none
D)all of the above

Question 16

Which of the relationship is correct in Permanent magnet DC motor?

A)T ? (I(A)2
B)T ? (I(A)0
C)T ? Ia
D)T2 ? Ia

Question 17

Which of the relationship is correct in Permanent magnet DC motor?

A)E ? (N)
B)E ? (N).
C)E ? N
D)E2 ? N.

Question 18

Who made the first solar cell?

A)Gerald Pearson
B)Tim Bell
C)Tim Cook
D)Nicola Tesla

Question 19

When was the first solar cell invented?

A)1950
B)1954
C)1965
D)1952

Question 20

Which of the following is an advantage of electric traction over other methods of traction ?

A)Faster acceleration
B)No pollution problems
C)Better braking action
D)All of the above

Question 21

Which of the following is the voltage for single phase A.C. system ?

A)22 V
B)440 V
C)5 kV
D)15 kV

Question 22

Long distance railways use which of the following ?

A)200 V D.C.
B)25 kV single phase A.C.
C)25 kV two phase A.C.
D)25 kV three phase A.C.

Question 23

The speed of a locomotive is controlled by

A)flywheel
B)gear box
C)applying brakes
D)regulating steam flow to engine

Question 24

Main traction systems used in India are, those using

A)electric locomotives
B)diesel engine locomotives
C)steam engine locomotives
D)all of the above