The power factor of a good choke coil is:
1. Nearly zero
2. Exactly zero
3. Nearly one
4. Exactly one
1. | R4 |
2. | R2 |
3. | R |
4. | Cannot be found with the given data |
The phase difference between the current and voltage of LCR circuit in series combination at resonance is
1. 0
2. π/2
3. π
4. –π
In a series resonant circuit, the ac voltage across resistance R, inductance L and capacitance C are 5 V, 10 V and 10 V respectively. The ac voltage applied to the circuit will be
1. 20 V
2. 10 V
3. 5 V
4. 25 V
In a series LCR circuit, resistance R = 10Ω and the impedance Z = 20Ω. The phase difference between the current and the voltage is
1. 30°
2. 45°
3. 60°
4. 90°
In the circuit shown below, the AC source has voltage V=20cos(ωt) volts with ω=2000 rad/sec. The amplitude of the current is closest to:
1. 2 A
2. 3.3 A
3. 2√5
4. √5 A
In an ac circuit the reactance of a coil is √3 times its resistance, the phase difference between the voltage across the coil to the current through the coil will be:
1. π/3
2. π/2
3. π/4
4. π/6
The power factor of an ac circuit having resistance (R) and inductance (L) connected in series and an angular velocity ω is
1. R/ωL
2. R/(R2+ω2L2)1/2
3. ωL/R
4. R/(R2−ω2L2)1/2
An inductor of inductance L and resistor of resistance R are joined in series and connected by a source of frequency ω.
The power dissipated in the circuit is:
1. (R2+ω2L2)V
2. V2R(R2+ω2L2)
3. V(R2+ω2L2)
4. √R2+ω2L2V2