a) Increasing the field current b) Increasing its speed c) Increasing the armature resistance d) All of these Ans: (b)
a) Short-circuited terminals b) Reversed terminal of field winding c) Reversed terminal of armature winding d) Disconnected load Ans: (a)
a) 85 – 95 % b) 75 – 85 % c) 65 – 75 % d) 55 – 65 % Ans: (a)
a) Interpoles additionally supply mmf for counter acting the reactance voltage induced in the coil under going commutalion b) Action of interpoles is localized c) Interpoles also helps in equalizing distribution of current in brushes d) (Both (a) and b) Ans: (d)
a) High resistance of the brushes b) Reactance voltage c) Armature reaction d) Quick reversal of current in the coil Ans: (b)
a) Cross magnetizes it b) Demagnetizes it c) Strengthens the main flux d) Both (a) and (b) Ans: (d)
a) Rated voltage is less than no load voltage b) Series field AT produces same voltage at rated and no load c) Series field AT produces rated voltage grated then and no load d) Series field AT produces rated voltage less than no load Ans: (b)
a) Increasing the resistance of the brushes b) Reducing the number of turns in armature coil c) Neutralizing reactance voltage d) All of these Ans: (d)
a) To increase the series flux b) Because both will pass equal currents to the load c) To reduce combined effect of armature reaction of both d) To increase speed and hence generated emf. Ans: (b)
a) Not develop voltage at all b) Generate maximum power c) Generate maximum voltage d) None of these Ans: (a)
a) Polarities must be same b) Phase sequence must be same c) Polarities and voltage must be same d) Both (b) and (c) Ans: (d)
 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 |