Ac motor

REE Board Exam October 1997.

A single phase induction motor is rated 5 hp, 75% power factor and 220 volts. What is its full load current?

• 22.5 amperes

• 20.5 amperes

• 16.5 amperes

• 18.5 amperes

EE Board Exam April 1990

A 5 hp, 3-phase motor draws current when connected to 230 V. Determine the current drawn by the motor if the power factor is 0.90 and efficiency of 83%.

• 12.53 A

• 15.13 A

• 13.25 A

• 13.25 A

REE Board Exam September 2001

Which of the following is not a reason why a single phase induction motor will not run?

• one of the current is made out of phase between the lines

• hysteresis

• shaded poles

• two windings displaced from each other

REE Board Exam October 1996

The following are types of AC motor starters except one

• reactance starter  l

• wye-delta starter

• across the line starter

• capacitance starter

Motor starting device that will reduce the voltage impressed at motor’s terminals during starting periods.

• autotransformer

• primary resistor-type

• wye-delta starter

• all of these

Basically all electric motors operate on the principle of repulsion or ______.

• induction

• magnetism

• resistance

• capacitance

The principle of operation of induction motor is based on

• Fleming’s right hand rule

• rotating magnetic field

• Faraday’s law

• Ohm’s law

A compensator is a device that is used with alternating current motors to ______

• boost the supply voltage during starting periods

• compensate for low power factor when motor is not fully loaded

• reduce the supply voltage during starting periods

• compensate for voltage drop in the circuit

A single-phase motor provided with a squirrel cage winding on its rotor in addition to its regular winding is called

• split-phase induction motor

• repulsion induction motor

• universal motor

• repulsion-start induction motor