# AC Circuits Questions and Answers

Physics

AC CircuitsIn an RLC circuit a resistor R=25Ω, an inductor L=30mHand a capacitor C=12µF are connected in series with an AC source with Vrms=80V and f=500Hz
i) Determine the total impedance.
ii) Determine the rms current in the circuit.
iii) Determine the phase angle.
iv) Determine the rms value of the voltage across R, L, and C.

Physics

AC CircuitsFind the Thevenin equivalent with respect to the terminals a,b for the circuit(Figure 1)if v = 300 V, i = 17 A.

Physics

AC CircuitsA 45 W light bulb operates with an effective ac voltage of 110 V.
(a) What is the effective current through the light bulb?
(b) From Ohm's law, what is the resistance of the light bulb?
Part Answer
(a)
(b)

Physics

AC CircuitsA 1.00mH inductor and one 1.00μF capacitor are connected in series. The current in the circuit is described by I = 20t where t is in seconds and I is in amperes. Initially, the capacitor has no charge. Determine
a. The voltage across the inductor as a function of time,
b.The voltage across the capacitor as a function of time
c.The time when the energy stored in the capacitor first exceeds that in the inductor.

Physics

AC Circuits011/12-13
O11 12 13
In the above circuit if R₁ R₂ R3, and the currents passing through the corresponding resistances are 1₁, 12, and 13. then,
11 12 13
V
O111213
R₂₁

Physics

AC CircuitsA 100Ω resistor, 2.00 mH inductor, and 50 µF capacitor are connected in series to an AC voltage source. If the maximum voltage is 75.0 V and the frequency is 500 Hz, what is the rms current in the circuit?

Physics

AC Circuits38. Magnets are involved in the production of electricity for many power
generators.
True
False

Physics

AC CircuitsA power station is located 120km from a town that requires 60MW of power. The transmission lines have a resistance of 0.100/km.
Determine the output voltage of the transformer at the power station so that the overall efficiency is 98 %, assuming that the transformers are 100% efficient.

Physics

AC CircuitsFind the charge on the capacitor in an LRC-series circuit at t = 0.04 s when L = 0.05 h, R = 3, C = 0.008 f, E(t) = 0 V, q(0) = 3 C, and i(0) = 0 A. (Round your answer to four decimal places.)
Determine the first time at which the charge on the capacitor is equal to zero. (Round your answer to

Physics

AC CircuitsA 65 Ω resistor, an 7.8 μF capacitor, and a 39 mH inductor are connected in series in an ac circuit.
Calculate the impedance for a source frequency of 30.0 kHz.

Physics

AC CircuitsAn electric motor is being powered with a voltage amplitude of 350 V at 60 Hz. The motor draws a current amplitude of 13.0 A. Find the root-mean-square current.

Physics

AC CircuitsAn electric motor is being powered with a voltage amplitude of 350 V at 60 Hz. The motor draws a current amplitude of 13.0 A.
Find the root-mean-square voltage.

Physics

AC CircuitsConsider the power dissipated in a series R-L-C circuit with R=3600, L = 120mH, C=0.800μF, V = 50V, and w=11300rad/s. The current and the voltages in this circuit are not in phase with each other. Using the values given, the phase angle was found to be 74°, and the current amplitude I was found to be 3.9x10-2 A. Calculate the power factor and the average power to the entire circuit and to each circuit element. If the inductance L in this circuit could be changed, what value of L would give a power factor of unity?

Physics

AC CircuitsWhen a resistance R is connected in series with an (non-resistive) element A, the electric current is found to lead the voltage by angle of 30°. When the same resistance is connected in series with (non-resistive) element B,
current lags by 60°. When R, A, B are connected in series, the phase difference between current and voltage is tan-1(k/√3)
Find the value of k.

Physics

AC CircuitsAn alternating current generator has an internal resistance Rg and an internal inductive reactance of magnitude Xg. It is used to supply power to a passive load consisting of a resistance R₁
(fixed) and a capacitive reactance of magnitude Xc. For maximum power to be delivered from the generator to the load the value of X, is equal to :
Rg
Xg
Equal and opposite of reactance of generator.
Equal in magnitude of impendence of generator.

Physics

AC CircuitsIf current amplitude is 5A and angular frequency of source is 100 rad/sec and resistance is 100 , inductance is 4 H and capacitance is 20 uF. The peak value of source voltage is 250 n
Find n.