| 1 |
Poor power factor results in all of the following EXCEPT.
Reduction in power losses
[other wrong options are – Overloading of transformers, Overloading of altemators, Reduction in load handling capacity of electrical system, ] |
| 2 |
The dual of a loop is
Node pair
[other wrong options are – Twig, Mesh, Tree, ] |
| 3 |
Higher the Q of a series circuit
Narrower its pass band
[other wrong options are – Broader its resonance curve, Greater its band width, Sharper its resonace, ] |
| 4 |
When an alternating current passes through an ohmic resistance the electrical power converted into heat is
True power
[other wrong options are – Apparent power, Reactive power, None of the above, ] |
EE SHORT NOTES AC FUNDAMENTALS 1
| 5 |
For the full wave rectified sine wave the r.m.s. value is
0.707 Imax
[other wrong options are – 0.636 Imax, 0.318 Imax ,Zero, ] |
| 6 |
In A.C. circuit laminated iron is invariably used in order to
Reduce eddy current loss
[other wrong options are – Increase heat radiation, Make assembly cheap and easier, Reduce circuit permeability, ] |
| 7 |
In a circuit containing R, L and C, power loss can take place
R only
[other wrong options are – C only, L only, All of the above, ] |
| 8 |
All the rules and laws of D.C. circuit also supply to A.C. circuit containing
Resistance only
[other wrong options are – Capacitance only, Inductance only, All above, ] |
| 9 |
How much r.m.s. current does a 300 W. 200V bulb take from the 200 V, 50 Hz power line ?
1.5 A
[other wrong options are – 0.5A, 2A, 3A, ] |
EE SHORT NOTES AC FUNDAMENTALS 1
| 10 |
The r.m.s. value and mean value is the same in the case of
Square wave
[other wrong options are – Triangular wave, Sine wave, Half wave rectified sine wave, ] |
| 11 |
The period of a wave is
Time required to complete one cycle
[other wrong options are – The same as frequency, Expressed in amperes, None of the above, ] |
| 12 |
The capacitors for power factor correction are rated in terms of
kVAR
[other wrong options are – Voltage, VA, kW, ] |
| 13 |
Two sinusoidal quantities are said to be phase quadrature, when their phase difference is
90°
[other wrong options are – 0, 30°, 45°, ] |
EE SHORT NOTES AC FUNDAMENTALS 1
| 14 |
A coil with large distributed capacitance has a
High resonant frequency
[other wrong options are – Low resonant frequency, Low quality factor, Low resistance, ] |
| 15 |
A resonance curve for a series circuit is a plot of frequency versus
Current
[other wrong options are – Voltage, Impedance, Reactance, ] |
| 16 |
The unit of frequency of an A.C. signal is
Hertz
[other wrong options are – Cycle, Cycle-sec, Hertz/sec, ] |
| 17 |
The power taken by a 3-Φ load is given by the expression
√3 VL IL cosΦ
[other wrong options are – √3 VL IL sinΦ, 3 VL IL sinΦ, 3 VL IL
cosΦ, ] |
| 18 |
In an A.C. circuit, a low value of kVAR compared with kW indicates
High power factor
[other wrong options are – Low efficiency, Unity power factor, Maximum Load current, ] |
EE SHORT NOTES AC FUNDAMENTALS 1
| 19 |
In a pure resistive circuit
Current is in phase with the voltage
[other wrong options are – Current lags behind the voltage by 90°, Current leads the voltage by 90°, Current can lead or lag the voltage by 90°, |
| 20 |
Inductance affects the direct current flow
At the time of turning on and off
[other wrong options are – Only at the time of turning off, Only at the time of turning on, At all the time of operation, ] |
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