Surprise Quiz - II 20EI205

If a single motor drives a number of machines through belts from a common shaft, such a type of drive system is known as __________.

• individual drive

• complex motor drive

• multi-motor drive

• group drive

Which of the following device is mainly used in DC drives?

• Transistor

• Diode

• Thyristor

• TRIAC

The load cycle for a motor driving a power press will be __________.

• variable load

• continuous load

• continuous but periodical

• intermittent and variable load

The principle of step-up chopper can be employed for the ________.

• motoring mode

• regenerative mode

• plugging

• reverse motoring mode

In a single-phase fully controlled converter drive, the average DC output voltage is controlled by:

• Varying the input frequency

• Varying the firing angle of the SCRs

• Using a step-down transformer

• Changing the rotor resistance

In a three-phase converter drive, how many pulses of DC are generated per cycle of AC?

• 1 pulse

• 2 pulses

• 3 pulses

• 6 pulses

In a chopper drive, if the duty cycle is increased, the average output voltage:

• Increases

• Decreases

• Remains the same

• Fluctuates randomly

AC drives are primarily used for controlling the speed of which type of motor?

• Induction motor

• DC motor

• Universal motor

• Stepper motor

In induction motor drives, torque control is mainly achieved by adjusting:

• Input voltage

• Input frequency

• Rotor resistance

• Load resistance

AC induction motor drives are preferred in fans and blowers because:

• They provide a constant speed

• They allow variable speed operation for energy savings

• They do not require a power supply

• They operate on DC power