Prepare for NEET Physics Alternating Current with MCQs & PYQs on NEET.GUIDE. Access free practice, previous year questions, and expert solutions to tackle AC circuits confidently.
The quality factor (Q) of an LCR circuit is a measure of:
Energy stored in the inductor
Energy stored in the capacitor
Sharpness of resonance
Resistance of the circuit
In an LC circuit, the energy oscillates between the inductor and the capacitor. If a small resistance is introduced in the circuit, which of the following best describes the effect on the oscillations?
Undamped oscillations with constant amplitude
Damped oscillations with decreasing amplitude
The oscillations stop immediately
The frequency of oscillation increases
A choke coil and a resistor are connected in series to an AC source. If the inductance of the choke coil is and the resistance is , under what condition will the power consumed by the circuit be independent of the frequency of the AC source?
R << ΟL
R = ΟL
R >> ΟL
R = 0
An ideal transformer has 100 turns in the primary and 500 turns in the secondary. If the primary voltage is 120V and the primary current is 2A, what is the secondary current?
20 A
10 A
0.4 A
5 A
A step-up transformer operates on a 220V line and supplies a load of 2A. The ratio of the primary and secondary windings is 1:25. Determine the current in the primary, assuming an ideal transformer.
50 A
0.08 A
27.5 A
110 A
A choke coil having negligible resistance carries a current . Which of the following is true regarding the instantaneous power consumed by the coil?
It is constant and equal to zero.
It is constant and equal to .
It oscillates at a frequency of with a mean value of .
It oscillates at a frequency of with a mean value of zero.
A transformer has an efficiency of 80%. It works at 4 kW and 100 V. If the secondary voltage is 240 V, calculate the primary and secondary currents.
Primary current: 40 A, Secondary current: 20 A
Primary current: 50 A, Secondary current: 16.67 A
Primary current: 25 A, Secondary current: 33.33 A
Primary current: 60 A, Secondary current: 12.5 A
A 2200 V, 50 Hz AC source is connected to a series combination of a resistor and a choke coil . If the voltage across the resistor is 120 V, and across the inductor is 1600 V, the power consumed by the choke coil is:
256 W
320 W
0 W
128 W
A series R-L-C circuit with , , and is connected to an AC source with and variable frequency. At resonance, the average power dissipated in the circuit is:
2000 W
4000 W
1000 W
8000 W
In a series R-C circuit, the voltage across the capacitor lags the current by . If the frequency of the source is doubled, the phase difference between the voltage across the capacitor and the current will:
Increase
Decrease
Remain the same
Become zero
