Bissoy.com
Doctors Medicines MCQs Q&A

Related Questions

Consider the following statements: In the above figure, the curves pertain to the DC motor A. Speed vs Armature current characteristic of a DC shunt motor B. Torque vs Armature current characteristic of a DC shunt motor C. Speed vs Armature current characteristic of a DC series motor D. Torque vs Armature current characteristic of a DC series motor
A person purchases 10 used generators at Rs. 2,000 each. Accessories of Rs. 5,000 were used to repair and paint the generators. He was able to sell 6 generators at Rs. 2,500 each but incurred a loss of 10% in the whole deal. Find the selling price of each generator and loss percentage on each generator of remaining generators.
In an alternator, the armature winding is kept stationary while the field winding is kept rotating for the following reasons: 1. Armature handles very large current and high voltage 2. Armature fabrication, involving deep slots to accommodate large coils, is easy if armature is kept stationary 3. It is easier to cool the stator than the rotor Which of the above reasons are correct?
In DC generators, current is fed up to the external circuit from armature through _______
Consider the following statements with respect to synchronous machines. State whether these statements are true or false. (a) Armature reaction is demagnetising when a generating machine supplies zero power factor lagging current. (b) Armature reaction is magnetising when a generating machine supplies zero power factor leading current. (c) Armature reaction is mostly cross-magnetising, though it has a small demagnetising component, when a generating machine supplies unity power factor current.
Which of the following statements are true? a. As load increases armature current decreases, regardless of excitation. b. For under and over excited motors, power factor tends to approach zero with increase in load c. With normal excitation when load is increased, change in armature current is greater than in power factor which tends to become increasingly leading. d. Both with under and over excitation, change in power factor is greater than in armature current with increase in load.
Two statements are given, followed by two conclusions numbered I and II. Assuming the statements to be true, even if they seem to be at variance with commonly known facts, decide which of the conclusions logically follow(s) from the statements. Statements: Some candles are bulbs Some bulbs are generators Conclusions: I. Some candles are generators II. All candles are generators
A power system has three synchronous generators. The turbine-governor characteristics corresponding to the generators are P1 = 50(50 - f), P2 = 100(51 - f), P3 = 150(52 - f) Where, f denotes the system frequency in Hz, and P1, P2, P3 are the power outputs of the turbines in MW. Assuming generators and transmission network to be lossless, the system frequency for a load of 700 MW is
Consider the following statements regarding the starting of a dc shunt motor: a. External field resistance should be minimum b. External field resistance should be maximum c. Reduced voltage should be applied to the armature d. Increased voltage should be applied to the armature Which of the above statements are correct?
During the short-circuit test of a synchronous machine, which of the following are accounted for in the short-circuit test loss? (i), I2R loss in the armature winding due to the flow of short-circuiting (AC) current (ii) Local core loss caused by armature leakage flux (iii) Core loss due to resultant air-gap flux. (iv) Windage and friction loss