Circuits and Circuit Theory

51.Magnitude of current at resonance in R-L-C circuit

1. depends upon the magnitude of R
2. depends upon the magnitude of L
3. depends upon the magnitude of C
4. depends upon the magnitude of R, Land C

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52.Ohm is unit of all of the following except

1. inductive reactance
2. capacitive reactance
3. resistance
4. capacitance

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53.Poor power factor

1. reduces load handling capability of electrical system
2. results in more power losses in the electrical system
3. overloads alternators, transformers and distribution lines
4. results in more voltage drop in the line
5. results in all above

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54.Power factor of an electrical circuit is equal to

1. R/Z
2. cosine of phase angle difference be-tween current and voltage
3. kW/kVA
4. ratio of useful current to total cur¬rent Iw/I
5. all above

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55.Power factor of an inductive circuit is usually improved by connecting capacitor to it in

1. parallel
2. series
3. either (a) or (b)
4. none of the above

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56.Power factor of electric bulb is

1. zero
2. lagging
3. leading
4. unity

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57.Power factor of the following circuit will be unity

1. inductance
2. capacitance
3. resistance
4. both (a) and (b)

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58.Power factor of the following circuit will be zero

1. resistance
2. inductance
3. capacitance
4. both (b) and (c)

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59.Power factor of the system is kept high

1. to reduce line losses
2. to maximise the utilization of the capacities of generators, lines and transformers
3. to reduce voltage regulation of the line
4. due to all above reasons

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60.Pure inductive circuit

1. consumes some power on average
2. does not take power at all from a line
3. takes power from the line during some part of the cycle and then returns back to it during other part of the cycle
4. none of the above

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