a) For running different machine tools where several speeds are required b) For running paper machine requiring exact speed control c) For running electric vehicles d) For running rolling mills needing exact speed control Ans: (a)
a) Copper losses in the stator b) Friction and winding losses c) Sum of (a) and (b) above d) Total losses in the rotor on no load Ans: (d)
a) The frequency of rotor currents b) The frequency of stator currents c) Difference of the frequencies of the stator and rotor currents d) Sum of the frequencies of the stator and rotor currents Ans: (a)
a) Single-phase ac supply b) Three- phase ac supply c) Dc supply d) Supply obtained from an inverter Ans: (c)
a) Increases b) Decreases c) Remains constant d) Increases and then becomes constant Ans: (b)
a) Increases and its frequency decreases b) Increases and its frequency increases c) Decreases and its frequency increases d) Decreases and its frequency decreases Ans: (a)
a) Slip ring induction motor b) Squirrel cage induction motor c) Salient pole synchronous motor d) Wound rotor synchronous motor Ans: (a)
a) Run at dangerously high speed b) Stop c) Continue to run depending on load d) None of these Ans: (c)
a) That the motor stops b) Current decreases slightly c) Speed reduces slightly d) Motor heats up with passage of time Ans: (d)
a) Single excited machine b) Double excited machine c) Machine in which three-phase supply is fed to both stator and rotor winding d) None of these Ans: (c)
 Multiple Choice Question (MCQ) of Electronics page-17:241. Which of the following statement is true? a) The saturation voltage VCF of silicon transistor is more than germanium transistor. b) The saturation voltage VCE for germanium transistor is more than silicon transistor. c) The saturation voltage VCE for silicon transistor is same as that for germanium. d) The saturation voltage VCE for silicon transistor is lower than germanium transistor. |
Multiple Choice Question (MCQ) of Electronics page-16:226. Which of the following statement is correct? a) Inner electrons are always present in the semiconductor. b) Bound electrons are always present in the semiconductor. c) Free electrons are always present in the semiconductor. d) Inner and bound electrons are always present in the semiconductor. |
Multiple Choice Question (MCQ) of Electronics page-15:211. The materials whose electrical conductivity is usually less than 1 × 106 mho/m are a) Semiconductors b) Conductors c) Insulators d) Alloys |
Multiple Choice Question (MCQ) of Electronics page-14:196. In which of the following device the base resistors are not added in the package but added externally? a) UJT b) CUJT c) PUT d) None of the above |
Multiple Choice Question (MCQ) of Electronics page-13:181. The conduction in JEFT is always by the a) Majority carriers b) Minority carriers c) Holes d) Electrons e) Holes and electrons simultaneously |