Voltage and current in an A.C. circuit is given by
Wattful current in the circuit is-
Which of the following devices is not based on Faraday's law of electromagnetic induction?
1. AC generator
2. Speedometer
3. Induction motor
4. DC motor
Current l through an inductor is increasing according to . Variation of the rate of increment of its energy with time t is correctly shown in the graph
1. 2.
3. 4.
A time-varying current is given by Its r.m.s. value is (symbols have usual meanings)
An alternating voltage at different frequencies is applied across a capacitor C as shown in the figure. Which of the following graphs between RMS current observed by an ammeter and angular frequency of voltage is correct?
1. 2.
3. 4.
It is found that the current through the LCR series circuit is at its maximum. If are potential differences across resistance, capacitor, and inductor respectively, then which of the following is correct?
1. | \(V_r=V_L>V_C\) |
2. | \(V_R \neq V_L=V_C\) |
3. | \(V_R \neq V_L \neq V_C\) |
4. | \(V_R=V_C \neq V_L\) |
In a series L-C-R circuit, different physical quantities vary with frequency . Which of the following curves represent the correct frequency variation of the corresponding quantity?
1. Curve (l) for R
2. Curve (ll) for
3. Curve (lll) for
4. All of these
For the circuit shown in figure below, the ammeter reads 1.6 A and ammeter read 0.4 A If is angular frequency and is frequency of ac, then
If the reading of and are 100 V each, the reading of is
1. 0 V
2. 100 V
3. 200 V
4. Cannot be determined by given information
If current \(i_1=3A sin \omega t\) and current \(i_2=4A cos \omega t,\) then \(i_3\) is:
1. \(5 A \sin \left(\omega t+53^{\circ}\right) \)
2. \(5 A \sin \left(\omega t+37^{\circ}\right) \)
3. \(5 A \sin \left(\omega t+45^{\circ}\right) \)
4. \( 5 A \sin \left(\omega t+30^{\circ}\right)\)