A coil of inductive reactance of 31 Ω has a resistance of 8 Ω. It is placed in series with a condenser of capacitive reactance 25 Ω. The combination is connected to an a.c. source of 110 V. The power factor of the circuit is:
1. 0.56
2. 0.64
3. 0.80
4. 0.33
An alternating voltage source is connected to a series R-C circuit. Consider two situations:
1. | When the capacitor is air-filled. |
2. | When the capacitor is mica filled. |
If the current through the resistor is I and the voltage across the capacitor is V, then:
1. \(V_a < V_b\)
2. \(V_a > V_b\)
3. \(i_a > i_b\)
4. \(V_a = V_b\)
A resistance 'R' draws power 'P' when connected to an AC source. If an inductance is now placed in series with the resistance, such that the impedance of the circuit becomes 'Z' the power drawn will be:
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 |
The figure shows the variation of R, XL, and XC with frequency f in a series of L, C, and R circuits. For which frequency point is the circuit inductive?
1. | A | 2. | B |
3. | C | 4. | All points |
One 10 V, 60 W bulb is to be connected to 100 V line. The required induction coil has a self-inductance of value: (f = 50 Hz)
1. 0.052 H
2. 2.42 H
3. 16.2 mH
4. 1.62 mH
In an LCR series network, . The supply voltage will be:
1. 25 V
2. 75 V
3. 35 V
4. Zero
In a step-up transformer, the turn ratio is 1:2 . A Leclanche cell (e.m.f. 1.5 V) is connected across the primary coil. What would be the voltage developed in the secondary coil?
1. | 3.0 V | 2. | 0.75 V |
3. | 1.5 V | 4. | Zero |