In an L-R circuit, the inductive reactance is equal to the resistance R of the circuit. An emf of E = E0cos(ωt) is applied to the circuit. The power consumed by the circuit is:
1.
2.
3.
4.
In the series LCR circuit, the voltmeter and ammeter readings are respectively
1. V = 100 V, I = 2 A
2. V = 1000 V, I = 5 A
3. V = 1000 V, I = 2 A
4. V = 300 V, I = 1 A
The current flowing through the resistor in a series L–C–R a.c. circuit in resonance is I . Now the inductor and capacitor are connected in parallel and joined in series with the resistor as shown in figure. The current in the circuit is now -(Symbols have their usual meaning)
1. equal to I
2. more than I
3. less than I
4. zero
In a series LCR circuit, the frequencies and at which the current amplitude falls to of the current amplitude at resonance are separated by frequency interval
1.
2.
3.
4. RC
In a RLC series circuit shown, the readings of voltmeters are 100 V and 120 V, respectively. If source voltage is 130 V
1. Voltage across resistor is 50 V.
2. Voltage across inductor is 86.6 V.
3. Voltage across capacitor is 206.6 V.
4. all of these
An alternating voltage V = V0 sin t is connected to a capacitor of capacity C0 through an AC ammeter of zero resistance. The reading of ammeter is
1.
2.
3.
4. none of these
In the circuit shown in the figure, if both the bulbs B1 and B2 are identical, then
1. their brightness will be the same
2. as frequency of supply voltage is increased, brightness of B1 will decrease and that of B2 will increase
3. as frequency of supply voltage is increased, brightness of B1 will increase and that of B2 will decrease
4. only B2 will glow because the capacitor has infinite impedance.
A capacitor of capacity 2 F is charged to a potential difference of 12V. It is then connected across an inductor of inductance 0.6 mH. The current in the circuit at a time when the P.D. across the capacitor is 6.0 V is
1. 0.6 A
2. 1.2 A
3. 2.4 A
4. 3.6 A
When a resistance of 10 Ω is connected in series with an inductor across an AC voltage source, current lags voltage by a phase . If same resistance is connected in series with a capacitor with same AC source, the current leads the voltage by phase , then the ratio of is ( in Henry/ Farad)
1. 100
2. 10
3. 1000
4. can’t be determine
A capacitor and resistor are connected with an A.C. source as shown in figure. Reactance of capacitor is XC = 3Ω and resistance of resistor is 4Ω. Phase difference between current I and I1 is
1. 900
2. zero
3. 53º
4. 37º