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Ac basic
| 1-Dont try to cram or spend more time here just read it fast and cover syllabus then practice MCQ's cheptor of same topic to check your progress. . |
| 2-Wrong options are also given but dont concentrate there, Right answer is in bold format. |
| Q1 ⇒ Power factor of the following circuit will be zero both (b) and (c). [other wrong options] [Discuss in forum] |
| Q2 ⇒ A 100 W, 100 V bulb is to be supplied from 220 V, 50Hz supply.
Which of the following arrangements is preferable? Additional pure inductance in series with lamp. [other wrong options] [Discuss in forum] |
| Q3 ⇒ Capacitive susceptance is a measure of a purely capacitive circuit' s ability to pass current. [other wrong options] [Discuss in forum] |
| Q4 ⇒ In a series RLC circuit at resonance, the magnitude of voltage
developed across the capacitor can be greater than the inpu voltage however, it is 90° out of phase with the input voltage. [other wrong options] [Discuss in forum] |
| Q5 ⇒ A high Q coil has low losses. [other wrong options] [Discuss in forum] |
| Q6 ⇒ Tn an R-L-C series resonant circuit, if inductance of the circuit is
made double and the capacitance is made half, which of the
following will be affected? Selectivity of the circuit [other wrong options] [Discuss in forum] |
| Q7 ⇒ According to maximum power transfer theorem, when is the
maximum power absorbed by one network from another network? The impedance of one is the complex conjugate of the other. [other wrong options] [Discuss in forum] |
| Q8 ⇒ To improve the pf in three-phase circuits, the capacitor bank is
connected in delta to make capacitance very small. [other wrong options] [Discuss in forum] |
| Q9 ⇒ In a 3-phase supply, floating neutral is undesirable because it may
result in ____across the load. unequal line voltages [other wrong options] [Discuss in forum] |
| Q10 ⇒ An even waveform when expressed in exponential fourier series
will contain only real coefficient [other wrong options] [Discuss in forum] |
| Q11 ⇒ A component that opposes the change in circuit current is inductance. [other wrong options] [Discuss in forum] |
| Q12 ⇒ Laplace transform of the output response of a linear system is the
system transfer function when the input is an impulse signal [other wrong options] [Discuss in forum] |
| Q13 ⇒ The rms value of the resultant current in a wire which carries a dc
current of 10 A and a sinusoidal alternating current of peak value
20 A is 17.3 A [other wrong options] [Discuss in forum] |
| Q14 ⇒ A pure capacitance connected across 50 Hz, 230 V supply
consumes 0.04 W. This consumption is attributed to both (a) and (b). [other wrong options] [Discuss in forum] |
| Q15 ⇒ The power consumed in an inductive circuit will be VI cos φ [other wrong options] [Discuss in forum] |
| Q16 ⇒ two terminal black box contains one of the R-L-C elements. The
black box is connected to a 220 V ac supply. The current through
the source is I. When a capacitance of 0.1 F is inserted in series
between the source and the box, the current through the source is
2 I. The element is an inductance. [other wrong options] [Discuss in forum] |
| Q17 ⇒ A resistance of 'R'ω and inductance 'L' H are connected across
240 V, 50Hz supply. Power dissipated in the circuit is 100 W and
the voltage across R is 100 V. In order to improve the pf to unity,
the capacitor that is to be connected in series should have a value of 43.7 µF [other wrong options] [Discuss in forum] |
| Q18 ⇒ A coil having a resistance of 5 ω and inductance of 0.1 H is
connected in series with a condenser of capacitance 50 pF. A
constant alternating voltage of 200 V is applied to the circuit. The
voltage across the coil at resonance is 1,800 volts [other wrong options] [Discuss in forum] |
| Q19 ⇒ Consider the following statementsregarding the frequency response curve of a series R-L-C circuit. 1. At half power freqLlencies, the current in the circuit is onehalf of the current at resonant frequencies. 2. At half-power frequencies, the power factor angle of the circuit is 45°. 3. At resonant frequency, the power factor angle of the circuit is 4. Maximum power occurs at resonant frequency. 2 and 4 are correct. [other wrong options] [Discuss in forum] |
| Q20 ⇒ parallel circuit is said to be in resonance when the admittance is
purely conductive. [other wrong options] [Discuss in forum] |
| Or |