7) Short-circuit test on an induction motor cannot be used to determine:A. windage lossesB. copper lossesC. transformation ratioD. power scale of circle diagramE. All above8) The shape of the torque/slip curve of induction motor is:A. parabolaВ. һурerbolaC. rectangular parabolaD. straigth lineE. rectangular9) A brushless exciter used when the synchronous machine is:A. SmallB. LargeC. MediumD. Very smallE. All above10) If the capacitor of a single-phase motor is short-circuited:A. the motor will not startB. the motor will runC. the motor will run in reverse directionD. the motor will run in the same direction at reduced r.p.m.E. All above11) A centrifugal switch is used to dis- connect 'starting winding when motor has:A. run for about 1 minuteB. run for about 5 minutesC. picked up about 50 to 70 per cent of rated speedD. picked up about 10 to 25 per cent of rated speedE. picked up about 0 to 10 per cent of rated speed12)If starting winding of a single-phase induction motor is left in the circuit, it will:A. run fasterB. spark at light loadsC. draw excessive current and overheatD. run slowerE. spark at rated loads13)The capacitors used in single-phase capacitor motors have no:A. voltage ratingB. dielectric mediumC. polarity markingD. definite valueE. All above

7) Short-circuit test on an induction motor cannot be used to determine: A. windage losses B. copper losses C. transformation ratio D. power scale of circle diagram E. All above 8) The shape of the torque/slip curve of induction motor is: A. parabola B. hyperbola C. rectangular parabola D. straigth line E. rectangular 9) A brushless exciter used when the synchronous machine is: A. Small B. Large C. Medium D. Very small E. All above 10) If the capacitor of a single-phase motor is short-circuited: A. the motor will not start B. the motor will run C. the motor will run in reverse direction D. the motor will run in the same direction at reduced r.p.m. E. All above

7) Short-circuit test on an induction motor cannot be used to determine: A. windage losses B. copper losses C. transformation ratio D. power scale of circle diagram E. All above 8) The shape of the torque/slip curve of induction motor is: A. parabola B. hyperbola C. rectangular parabola D. straigth line E. rectangular 9) A brushless exciter used when the synchronous machine is: A. Small B. Large C. Medium D. Very small E. All above 10) If the capacitor of a single-phase motor is short-circuited: A. the motor will not start B. the motor will run C. the motor will run in reverse direction D. the motor will run in the same direction at reduced r.p.m. E. All above

Delmar's Standard Textbook Of Electricity

7th Edition

ISBN:9781337900348

Author:Stephen L. Herman

Publisher:Stephen L. Herman

Chapter35: Harmonics 916

Section: Chapter Questions

Problem 3RQ: Would a positive-rotating harmonic or a negative-rotating harmonic be more harmful to an induction...

See similar textbooks

Similar questions

Three Phase Induction Mot... The relative speed of stator magnetic field with respect to rotor of a 30 induction motor with 4 pole, 50 Hz frequency. If the slip is 0.05.
The resistance and reactance per phase of the rotor of a 3-phase induction motor are 0.6 ohm and 5 ohms respectively. The induction motor has a star-connected rotor and when the stator is connected to a supply of normal voltage, the induced e.m.f. between the slip rings at standstill is 80 V. Calculate the current in each phase and the power factor at starting when (i) the slip-rings are shorted, (ii) slip-rings are connected to a star-connected resistance of 4 ohm per phase.
Frequency is 60Hz...
Q3/ A/ Compare between de series and shunt generator. Q3/ B/ Briefly explain the commutating process in dc machine.
What are the main parts of an single phase induction motor? Explain the function Jeach,
IV. What are the various losses in an induction motor? On what actors do they depend?
I need the answer as soon as possible
Discuss the behaviour of an induction motor when it is rotating at synchronous speed.
Discuss the effects of rotor resistance in T-S characteristics of 3 phase induction motor.
A short shunt compound DC generator supplies a load current of 10A at a voltage of 10 volts. If the resistance of armature, shunt field and series field windings are 0.001 ohm, 1 ohm 0.00 ohm respectively. a) Draw the the figure. And find the generated voltage.
a) Explain how the power flows in an induction machine, where losses occur and how they can be calculated, along with typical percentage values that you would expect to observe. b) Briefly explain the differences between synchronous motors and induction motors. You should describe the construction and operation of each motor, and how power is distributed to the rotor. c) A 415V star-connected synchronous induction motor has a stator resistance of 0.5ohms per phase and a combined rotor and exciter resistance of 2 ohms. On no-load and with unity power factor, the motor draws a line current of 5 amperes.If the excitation current is 10 amperes under no-load unity power factor conditions and 20 amperes under load condition, what is the efficiency of the motor when the line supply current is 100 amperes?
Subject- Rotating AC Machines. Explain in detail, Synchronous motor as a synchronous condenser.