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 |
A 220 V, 50 Hz ac source is connected to an inductance of 0.2 H and a resistance of 20 ohms in series. How much current flows across the circuit?
1. 10 A
2. 5 A
3. 33.3 A
4. 3.33 A
When a step-down transformer is connected to a 2400 volt line, the output load receives 80 amps of current. The ratio of the turns in the primary and secondary coils is 20:1. If transformer efficiency is 100%, then the current flowing in the primary coil will be:
1. | 1600 A | 2. | 20 A |
3. | 4 A | 4. | 1.5 A |
A generator produces a voltage that is given by V = 240 sin 120 t, where t is in seconds. The frequency and r.m.s. voltage are:
1. | 60 Hz and 240 V |
2. | 19 Hz and 120 V |
3. | 19 Hz and 170 V |
4. | 754 Hz and 70 V |