The diagram shows a capacitor C and a resistor R connected in series to an ac source. V1 and V2 are voltmeters and A is an ammeter:
Consider now the following statements
I. Readings in A and V2 are always in phase
II. Reading in V1 is ahead in phase with reading in V2
III. Readings in A and V1 are always in phase
Which of these statements is/are correct?
(1) I only
(2) II only
(3) I and II only
(4) II and III only
In the circuit shown in figure neglecting source resistance the voltmeter and ammeter reading will respectively, will be
(1) 0V, 3A
(2) 150V, 3A
(3) 150V, 6A
(4) 0V, 8A
In the circuit shown in the figure, the ac source gives a voltage Neglecting source resistance, the voltmeter and ammeter reading will be:
(1) 0V, 0.47A
(2) 1.68V, 0.47A
(3) 0V, 1.4 A
(4) 5.6V, 1.4 A
An ac source of angular frequency ω is fed across a resistor r and a capacitor C in series.
I is the current in the circuit. If the frequency of the source is changed to ω/3 (but maintaining the same voltage), the current in the circuit is found to be halved. Calculate the ratio of reactance to resistance at the original frequency ω.
1.
2.
3.
4.
For a series RLC circuit, R = XL = 2XC. The impedance of the circuit and phase difference between V and i will be:
1.
2.
3.
4.
In the adjoining ac circuit the voltmeter whose reading will be zero at resonance is
(1) V1
(2) V2
(3) V3
(4) V4
In the adjoining figure, the impedance of the circuit will be:
(1) 120 ohm
(2) 50 ohm
(3) 60 ohm
(4) 90 ohm
In a series LCR circuit, which one of the following curves represents the variation of impedance (Z) with frequency (f)?
1. | 2. | ||
3. | 4. |
The variation of the instantaneous current (I) and the instantaneous emf (E) in a circuit are shown in the figure. Which of the following statements is correct?
1. | The voltage lags behind the current by π/2. |
2. | The voltage leads the current by π/2. |
3. | The voltage and the current are in phase. |
4. | The voltage leads the current by π. |
The figure shows the variation of R, XL, and XC with frequency f in a series L, C, R circuit. Then for what frequency point, the circuit is inductive:
(1) A
(2) B
(3) C
(4) All points