Objective Questions on AC Single Phase Motor for Electrician Trade
| Sr. No. | Questions with options |
| 1 | What is the working principle of single phase induction motor?
(a) Lenz’s law (b) Joule’s law (c) Faraday’s laws of electrolysis (d) Faraday’s laws of electromagnetic induction Ans – (a) |
| 2 | What is the working principle of split phase motor?
(a) Lenz’s lwa (b) Joule’s law (c) Faraday’s laws of electrolysis (d) Faraday’s laws of electromagnetic induction Ans – (a) |
| 3 | Which type of A.C single phase motor is classified under commutator motor type?
(a) Stepper motor (b) Repulsion motor (c) Shaded pole motor (d) Permanent capacitor motor Ans –(b) |
| 4 | Which method is adopted to start the single phase induction motor?
(a) Split phase method (b) Varying supply voltage method (c) Reversal of input supply terminals (d) Reversal of running coil connection Ans – (a) |
| 5 | Which type of winding wire is used for rewinding submersible pumps?
(a) PVC covered copper wire (b) Super enameled copper wire (c) Single cotton covered copper wire (d) Double cotton covered copper wire Ans – (a) |
| 6 | Which type of AC single phase motor having low starting torque?
(a) Induction start induction run motor (b) Capacitor start induction run motor (c) Capacitor start capacitor run motor (d) Resistance start induction run motor Ans – (d) |
| 7 | What is the function of centrifugal switch in single phase motors?
(a) Maintain constant speed (b) Break the starting winding (c) Break the running winding (d) Protect the motor from over loading Ans – (b) |
| 8 | Which is the application of universal motor?
(a) Jet pump (b) Food mixer (c) Teleprinter (d) Compressor Ans – (b) |
| 9 | Which single phase motor is fitted with wound rotor?
(a) Repulsion motor (b) Shaded pole motor (c) Permanent capacitor motor (d) Capacitor start capacitor run motor Ans – (a) |
| 10 | What is the relation between running winding and starting winding of a single phase induction motor with respect to resistance?
(a) Both resistances will be equal (b) Running winding is less, starting winding more (c) Running winding is more, starting winding is less (d) Running winding is less, starting winding is infinity Ans – (b) |
| 11 | How the direction of rotation of a capacitor start induction run motor is reversed?
(a) By changing the supply terminals (b) By changing the capacitor connections (c) By interchanging main winding terminals (d) By interchanging both main and auxiliary winding terminals Ans – (c) |
| 12 | Which single phase motor tapped field speed control method is employed?
(a) Universal motor (b) Shaded pole motor (c) Capacitor start induction run motor (d) Capacitor start capacitor run motor Ans – (a) |
| 13 | Which type of single phase induction motor is used in food mixter?
(a) Universal motor (b) Repulsion motor (c) Shaded pole motor (d) Permanent capacitor motor Ans – (a) |
| 14 | What is the angular displacement between starting and running winding of a single phase induction motor?
(a) 45 electrical degree (b) 60 electrical degree (c) 90 electrical degree (d) 120 electrical degree Ans – (c) |
| 15 | Why the hysteresis motor is suitable for sound recording instruments?
(a) Small in size (b) High efficiency (c) Noiseless operation (d) Less error operation Ans – (c) |
| 16 | Which motor is preferred for domestic water pumps?
(a) Universal motor (b) Repulsion motor (c) Shaded pole motor (d) Capacitor start motor Ans – (d) |
| 17 | Which type of motor has relatively small starting torque?
(a) Universal motor (b) Capacitor start capacitor run motor (c) Capacitor start induction run motor (d) Resistance start induction run motor Ans – (d) |
| 18 | Which is the function of centrifugal switch in split phase motor?
(a) Protects from over current (b) Maintains constant speed (c) Protect the motor form over loading (d) Make and break the starting winding from supply Ans – (d) |
| 19 | How to produce starting torque in a shaded pole fan motor?
(a) Using rings on poles (b) Using capacitor on winding circuits (c) Interchanging cage rotor windings by switch (d) Interchanging the field coil windings by switch Ans-(a) |
| 20 | What is the reason to use a permanent capacitor in fan motor circuit?
(a) Speed regulation (b) Lower power consumption (c) Splitting of phase for torque (d) Controlling electrical interference Ans –(c) |
| Data Collected By – Rashmi | |
| Published On – 27th May 2022 | |
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