Top 250+ Solved Control of Electric Drives MCQ Questions Answer
Q. When an electric train is moving down a hill the DC motor operates as a DC
a. Series motor
b. Series generator
c. Shunt motor
d. Shunt generator
Q. Speed controlled by variation of field flux results in
a. Constant power Drive
b. Variable power Drive
c. Constant torture Drive
d. Variable torque Drive
Q. The slip power recovery scheme is used in induction motor for speed control in the range
a. Above synchronous speed
b. Below synchronous speed
c. Both above and below synchronous speed
d. None of the above
Q. The pair used for frequency converter is
a. Squirrel cage induction motor and synchronous motor
b. Sleep ring induction motor and a synchronous motor
c. Sleep ring induction motor and squirrel cage induction motor
d. All of the above
Q. The motor in close are used for collieries, chemical plant is
a. Flame proof type
b. Splash proof type
c. Totally enclosed type
d. Pipe ventilated type
Q. The motor enclosure used in wood-working industry is
a. Protected type
b. Totally enclosed fan cooled type
c. Flame proof type
d. Splash proof type
Q. The motor enclosure used for industrial purposes is
a. Protected type
b. Drip proof type
c. Totally enclosed type
d. Open type
Q. Ball-bearings are
a. Used up to 75 kW motors
b. Of long life and low friction loss
c. Costlier and noisy particularly at high speed motor
d. All of the above
Q. Sleeve bearings
a. Are normally of bronze
b. Have self lubricating properties
c. Are used where noise is to be avoided
d. All of the above
Q. Hot bearings of a DC motor may be caused by
a. Poor ventilation
b. Incorrect voltage
c. Loose coupling
d. Lack of or dirty lubricant
Q. For very high speed ratio the indispensable drive is
a. Direct drive
b. Rope Drive
c. Chain drive
d. Any of the above
Q. 15 minute rated motors are suitable for
a. Light duty cranes
b. Medium duty cranes
c. Heavy duty cranes
d. All of the above
Q. For medium duty cranes the short time rating motor used is
a. 10 minutes
b. 15 minutes
c. 30 minutes
d. any of the above
Q. The cost of an induction motor will increase as
a. Horse power rating increases but rpm decreases
b. Horse power rating decreases but rpm increases
c. Horse power rating and operating speed increases
d. Horse power rating and operating speed decreases