Alternating Current Electromagnetic Waves Test Online

1. In a AC circuit the voltage and current are described by V = 200 sin (319t – π/6) volts and i = 50sin (314t + π/6)mA respectively. The average power dissipated in the circuit is:

2. In a circuit the coil of a choke:

3. An AC source of angular frequency ω is fed across a resistor R and a capacitor C in series. The current registered is I. If now the frequency of 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

4. In an AC circuit the potential differences across an inductance and resistance joined in series are respectively 16 V and 20 V. The total potential difference of the source is:

5. An inductor coil of inductance L is cut into two equal parts and both the parts are connected in parallel. The net inductance is:

6. The circuit shown below acts as:

7. If we decrease the frequency of the applied A.C. with a purely capacitive load, do (1) the amplitude of V_c and (2) amplitude of I_c increase, decrease of remain the same.

8. Which wavelength of sun is used finally as electric energy?

9. A capacitor of capacitance 2μF is connected in the tank circuit of an oscillator oscillating with a frequency of 1 kHz. If the current flowing in the circuit is 2 m A, the voltage across the capacitor will be:

10. In the circuit shown below what will be the reading of the voltmeter and ammeter? (Total impedance of circuit Z = 100

Ω)

11. An A.C. circuit containing only capacitance, the current:

12. A coke coil has:

13. A 50 Hz a.c. source of 20 volt is connected across R and C as shown in figurer. The voltage across R is 12 volt. The voltage across C is:

14. According to Maxwell’s hypothesis, changing of electric field give rise to:

15. The pressure exerted by an electromagnetic wave of intensity 1 (watt/m²) on a non-reflecting surface is: [c is the velocity of light]