1. In any electrical system reactive power (kVAR) should be
2. Total or apparent power is measured in
3. Power factor is always less than
4. Power factor can be improved using
5. Low power factor is generally due to
6. Power Factor is normally expressed in between
7. Ratio of average energy demand (load) to maximum demand (peak load) during a specific period is known as
8. The measure of the highest peak of electricity flow into the site during a half-hour period, in the period of a month is known as
9. __________ can measure active power, reactive power, apparent power
10. Electrical energy consumption is measured in
11. Power in a 3-phase load can be measured in the following methods
12. Total power in three wattmeter method
13. The instantaneous electrical power P delivered to a component is given by
14. Simplest in connection
15. Moving iron and coil system is a type of
16. Balance Weight is a type of
17. Fluid friction is type of
18. Coil and soft iron core arrangement is type of
19. Control weight is type of
20. Energy meter is a type of
21. Example of indicating instrument is
22. Ammeter measures
23. Which of the following statement is false?
24. ________________ devices are useful for onsite/multi location testing and measurement.
25. When the value of a measured variable changes slowly, the performance characteristics of an instrument to be considered are:
26. When the value of a measured variable changes very fast, the performance characteristics of an instrument to be considered are:
27. The degree of exactness (closeness) of measured value w.r.t. the true value is known as
28. A measure of consistency or repeatability of measurement is known as
29. The ratio of change in output (response) to change in input at a steady state condition is known as
30. To prevent high armature current during the starting of motors variable resistance is connected
31. For very small D.C. motor (e.g. 6v, 12v, motor) following starter is required
32. In case of power failure the starter arm is brought back to the off position. The mechanism is known as:
33. _______________________provides protection against an open field circuit
34. __________ is only used for D. C. series motor
35. Torque - Armature current (Ta - Ia) characteristic is also known as
36. Speed – Torque (N - Ta) characteristics is also known as
37. _______________ motor must never be started at no load
38. Type of constant speed motor is__________ motors.
39. Motor that shows the characteristics in between that of series and shunt motor is__________ motor.
40. When the armature and field winding of a D.C. generator is connected to a D.C. Source (e.g. battery) it will work like
41. The differenceTarmature – Tshaft is known as
42. Permanent magnet type D.C. generator are of
43. Poles of D.C. generator is magnetized using ____________ windings
44. A D.C. generator whose field magnet winding is supplied from an independent external D.C. source (e.g., a battery etc.) is called a
45. Generator can be classified as series, shunt and compound in the manner
46. As the field winding carries the entire load current, the field winding of ________________ has few turns of thick wire having low resistance
47. Type of current having +ve and –ve loop is known as
48. A.C. generating system has
49. D.C. generating system has
50. Interpoles are also known as
51. The brushes of D.C. generator are made of
52. The main problem in starting induction motors having large or medium size is
53. DOL starter
54. The current drawn by DOL starter induction motor is:
55. Star-Delta Starter are used for induction motor with
56. A soft starter controls and increases the ___________ for starting the induction motor
57. SI unit of torque is
58. Slip speed is equal to
59. Condition for maximum torque is
60. When rotor speed N is equal to Synchronous speed Ns then
61. At higher value of slip, torque is
62. Single phase induction motor has following number of stator winding:
63. Single phase induction motor is
64. A centrifugal switch disconnects the start winding when the motor reaches
65. Except for special capacitor start/capacitor run types, all single-phase motors are generally used for applications up to
66. The split-phase motor is also known as an
67. Advantage of induction motor
68. 3-phase induction motor has three windings placed apart at
69. The speed at which the magnetic field rotates is known as
70. Difference between the rotor speed (N) and rotating magnetic field speed (Ns) is called
71. Torque in induction motor is proportional to
72. One cycle is equal to
73. Which of the following statements is true
74. Resistance (R) is directly proportional to the
75. Resistance (R) is inversely proportional to the
76. The algebraic sum total of all the currents meeting at a point is
77.
The algebraic sum total of all the emf and all the voltage drops in a closed circuit or mesh is
78. Correct units for magnetic flux
79. Ability of a material to conduct magnetic flux through it
80. Magnitude of the induction e.m.f is equal to the
81. 1 Wb is equal to
82. Flux density is equal to
83. Direction of induced e.m.f. is given by:
84. The flux common to both the coils is known as
85. Unit of flux density is:
86. Direction of electro-magnetic induced current will be in such a direction so as to oppose the very cause which produces it
87. Example of statically induced emf
88. Shape of the A.C. current or voltage is known as
89. Sinusoidal wave is preferred over ramp, triangular or square wave because of:
90. Unit of frequency
91. Sinusoidal varying alternating quantity may be represented in the following way:
92. Angular velocity of phasor is given as
93. Two alternating quantities having same frequency but having different zero points are said to have:
94. Phase angle or angle of phase difference is denoted by
95. Alternating voltage or current can be added by any of the following methods
96. Different elements of an a.c. circuit may be
97. Unit of resistance:
98. Unit of inductance:
99. Unit of capacitance:
100. The power absorbed in a circuit with pure capacitance is
101. RLC circuit stands for
102. Frequency at which the impedance of the series circuit is at a minimum
103. Frequency > Resonating frequency when
104. Degree of current change with frequency above and below resonance
105. Power factor at resonance
106. Transmission line distribution and voltage regulation is better in
107. Neutral wire is present in
108. In star system Line voltage =
109. Alternators aredesigned as:
110. Four wire system
111. V = a + jb is type of
112. V = V? ?° is type of
113. Addition and subtraction of phasor is in
114. Multiplication of phasor is in
115. Division of phasor is in
116. Voltage is stepped up to 220 kV or 400 kV for transmission to long distances to
117. Efficiency of transformer is given as
118. Step up and step down of voltage is known as
119. Power is usually generated in large power stations at
120. Transformers which are used to transmit power between high-voltage networks
121. A three-phase transformer, compared to a bank of three single-phase transformers, for a given rating will be
122. Exciting current taken up by the primary winding
123. Eddy current and hysteresis loss
124. Loss in winding resistance
125. Losses caused due to eddy current in channels, bolts etc
126. Copper loss is given by
127. Change in terminal voltage when a load current at any power factor is applied, expressed as a fraction of the no-load terminal voltage is known as
128. Ratio of the change in the terminal voltage when a load at a given power factor is removed, and the load voltage is known as
129. The condition for maximum efficiency of a transformer is
130. All day efficiency of a transformer is considered for:
131. The flux Ř which links both the windings is called as
132.
The stationary part of the alternator is known as
133. The rotating part of an alternator is known as
134. Rings provided to supply current to the rotor winding is known as
135. Insulated copper wires are wound over steel structure to induce magnetic field when current is supplied
136. Such types of rotor are used for low to medium speed/rpm alternators
137. Magnitude of the induced emf in the coil rotating in a magnetic field in given as
138. Frequency of the induced emf is given as:
139. System to provide rotation to the alternator in known as
140. In India the frequency of alternating current is
141. A steam turbine rotates at 1500 rpm. Number of poles required in an alternator to generate 50 Hz alternator current is
142. Average e.m.fper conductor
143. Emf induced in an alternator
144. Average e.m.f induced inan alternator
145. Automatic electric switch which protects an electrical circuit from damage caused by overload or short circuit
146. MCB stands for:
147. About 90% of mechanical power in the industry is provided by
148. Stator core of induction motor is made of
149. Almost 90% of induction motors have
150. Skewing of rotor has the following advantages
151. Rotor resistance can be varied in
152. On increasing temperature, the resistance of a wire:
153. E.m.f (voltage) is induced in a coil or conduction when there is a change in magnetic flux linking the conductor.
154. The maximum value attained by an alternating quantity either voltage or current during one cycle is called
155. Step up transformer
156. Step down transformer
157. Transformer ratio
158. Turn ratio
159. Total number of conductor or coil sides per phase
160. Special safety circuit used primarily with outdoor circuits and in places where the risk of death by electric shock is greatest
161. Loss in winding resistance
162. Copper loss is given by
163. Exciting current taken up by the primary winding is
164. Losses caused due to eddy current in channels, bolts etc
165. Loss in winding resistance
166. Exciting current taken up by the primary winding is
167. Eddy current and hysteresis loss
168. Loss in winding resistance
169. Losses caused due to eddy current in channels, bolts etc
170. Copper loss is given by
171. SI unit of torque is
172. Slip speed is equal to
173. At start of motor rotor is stationary and the value of slip is
174. When rotor speed N is equal to Synchronous speed Ns then
175. At higher value of slip, torque is
176. For series motors armature torque is proportional to
177. When the armature and field winding of a D.C. generator is connected to a D.C. Source (e.g. battery) it will work like
178. For shunt motors armature torque is proportional to
179. 1 BHP =
180. The differencebetween armature torque and shaft torqueis known as
181. Power (P) is given by equation
182. Total power in three wattmeter (W1, W2 and W3) method is:
183. Power consumed by electromechanical energy meters is around: