1. The starting torque of a single phase induction motor is
(a) low.
(b) zero.
(c) very high.
(d) unity. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] B [/accordion-item][/accordion]
2. The capacitor start capacitor run induction motor act as a true 2-phase motor at
(a) no load.
(b) full load.
(c) all load.
(d) starting. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] B [/accordion-item][/accordion]
3. Which of the following type of capacitor is generally used in capacitor start single phase induction motor?
(a) Paper capacitor.
(b) Mica capacitor.
(c) Ceramic capacitor.
(d) Electrolytic capacitor. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] D [/accordion-item][/accordion]
4. A resistance split phase induction motor is used for
(a) low inertia load.
(b) high inertia load.
(c) very high inertia load.
(d) none of the above. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] A [/accordion-item][/accordion]
5. In a capacitor start induction motor, the capacitor is connected in series with
(a) starting winding.
(b) running winding.
(c) main winding.
(d) compensating winding. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] A [/accordion-item][/accordion]
6. In a capacitor start induction motor, the value of capacitor is determined by its
(a) power factor.
(b) speed.
(c) starting torque.
(d) supply voltage. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] C [/accordion-item][/accordion]
7. The purpose of using starting winding in single phase induction motor is to
(a) improve voltage regulation.
(b) increase speed.
(c) developed starting torque.
(d) improve power factor. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] C [/accordion-item][/accordion]
8. In a three phase induction motor, the speed regulation at full load is about
(a) 0.4%.
(b) 4%.
(c) 10%.
(d) 18%. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] B [/accordion-item][/accordion]
9. The main purpose of using of using phase advancer with large induction motor is to
(a) devolved starting torque.
(b) control speed.
(c) improve voltage regulation.
(d) improve power factor. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] D [/accordion-item][/accordion]
10. If the supply voltage of a three phase induction motor decreases, then its
(a) torque decreases.
(b) speed decreases.
(c) rotor current increases.
(d) all of the above. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] D [/accordion-item][/accordion]
11. In three phase induction motor, the value of slip at standstill condition is equal to
(a) zero.
(b) 0.1.
(c) 0.5.
(d) one. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] D [/accordion-item][/accordion]
12. Which starting method cannot be used for starting 3 phase squirrel cage induction motor?
(a) Star-Delta.
(b) Rotor resistance.
(c) Line resistance.
(d) Auto transformer. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] B [/accordion-item][/accordion]
13. Circle diagram of an induction motor can be used determine its
(a) power factor.
(b) efficiency.
(c) slip.
(d) all of the above. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] D [/accordion-item][/accordion]
14. When a 50 Hz 3-phase induction motor is operating at 2% slip, the frequency of rotor current is
(a) 1 Hz
(b) 2 Hz
(c) 50 Hz
(d) 100 Hz [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] A [/accordion-item][/accordion]
15. The stator core of a three phase induction motor is laminated in order to reduced the
(a) hysteresis losses.
(b) eddy current losses.
(c) copper losses.
(d) all of the above. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] B [/accordion-item][/accordion]
16. In an induction motor, the air gap flux density is usually kept low in order to
(a) Improve voltage regulation.
(b) reduce losses.
(c) improve speed regulation.
(d) improve power factor. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] D [/accordion-item][/accordion]