An inductor of \(20~\text{mH}\), a capacitor of \(100~\mu \text{F}\), and a resistor of \(50~\Omega\) are connected in series across a source of emf, \(V=10 \sin (314 t)\). What is the power loss in this circuit?
1. \( 0.79 ~\text{W} \)
2. \( 0.43 ~\text{W} \)
3. \( 2.74 ~\text{W} \)
4. \( 1.13 ~\text{W}\)

Subtopic:  Power factor |
 56%
Level 3: 35%-60%
NEET - 2018
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A \(50\) Hz AC source of \(20\) volts is connected across \(R\) and \(C\) as shown in the figure below. If the voltage across \(R\) is \(12\) volts, then the voltage across \(C\) will be:
           

1. \(8\) V
2. \(16\) V
3. \(10\) V
4. not possible to determine unless values of \(R\) and \(C\) are given
Subtopic:  Different Types of AC Circuits |
 74%
Level 2: 60%+
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What is the value of inductance \(L\) for which the current is a maximum in a series \(LCR\) circuit with \(C= 10~\mu\text{F}\) and \(\omega = 1000~\text{s}^{-1}\)?
1. \(10\) mH
2. \(100\) mH
3. \(1\) mH
4. Cannot be calculated unless \(R\) is known
Subtopic:  Different Types of AC Circuits |
 81%
Level 1: 80%+
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Alternating current cannot be measured by a DC ammeter because:
1. AC cannot pass through DC Ammeter.
2. AC changes direction.
3. Average value of current for the complete cycle is zero.
4. DC Ammeter will get damaged.
Subtopic:  AC vs DC |
 66%
Level 2: 60%+
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For a \(LCR\) series circuit with an AC source of angular frequency \(\omega\):
1. circuit will be capacitive if \(\omega>\frac{1}{\sqrt{LC}} \)
2. circuit will be inductive if \(\omega=\frac{1}{\sqrt{LC}} \)
3. power factor of circuit will be unity if capacitive reactance equals inductive reactance
4. current will be leading voltage if \(\omega>\frac{1}{\sqrt{LC}} \)
Subtopic:  Different Types of AC Circuits |
 80%
Level 1: 80%+
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In an \(L\text-R\) circuit, the inductive reactance is equal to the resistance \(R\) of the circuit. An emf of \(E = E_0 \cos(\omega t)\) is applied to the circuit. The power consumed by the circuit is:
1. \(\dfrac{E^2_0}{\sqrt{2}R}\) 2. \(\dfrac{E^2_0}{4R}\)
3. \(\dfrac{E^2_0}{2R}\) 4. \(\dfrac{E^2_0}{8R}\)
Subtopic:  Power factor |
 56%
Level 3: 35%-60%
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A series AC circuit has a resistance of \(4~\Omega\) and an inductor of reactance \(3~\Omega\). The impedance of the circuit is \(z_1\). Now when a capacitor of reactance \(6~\Omega\) is connected in series with the above combination, the impedance becomes \(z_2\). Then \(\frac{z_1}{z_2}\) will be:
1. \(1:1\)
2. \(5:4\)
3. \(4:5\)
4. \(2:1\)

Subtopic:  Different Types of AC Circuits |
 87%
Level 1: 80%+
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An inductor \((L)\) and resistance \((R)\) are connected in series with an AC source. The phase difference between voltage \((V)\) and current \((i)\) is \(45^{\circ}.\) If the phase difference between \(V\) and \(i\) remains the same, then the capacitive reactance and impedance of the \(LCR\) circuit will be:
1. \(2R, R\sqrt{2}\)
2. \(R, R\sqrt{2}\)
3. \(R, R\)
4. \(2R, R\sqrt{3}\)

Subtopic:  Different Types of AC Circuits |
 55%
Level 3: 35%-60%
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An \(AC\) voltage is applied to a resistance \(R\) and an inductor \(L\) in series. If \(R\) and the inductive reactance are both equal to \(3~ \Omega, \) then the phase difference between the applied voltage and the current in the circuit will be:

1. \( \pi / 4\) 2. \( \pi / 2\)
3. zero 4. \( \pi / 6\)
Subtopic:  Different Types of AC Circuits |
 76%
Level 2: 60%+
NEET - 2011
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A coil of self-inductance \(L\) is connected in series with a bulb \(B\) and an AC source. The brightness of the bulb decreases when:
1. Frequency of the AC source is decreased
2. The number of turns in the coil is reduced
3. A capacitance of reactance \(X_C = X_L\) is included in the same circuit
4. An iron rod is inserted in the coil
Subtopic:  Different Types of AC Circuits |
 71%
Level 2: 60%+
NEET - 2013
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