Exam 30: Alternating Current Circuits

Consider an series LCR circuit,consisting of a 20-micro Farad capacitance,a 10-milli-Henry inductance,and a 23-Ohm resistor.This circuit is fed by a sinusoidally alternating emf with an amplitude of 2.4 V.What is the maximum instantaneous current in the circuit at a frequency f = 50 Hz?

Consider a series RLC circuit consisting of a 6.75- $\varOmega$ resistor,a 8.60-mH inductor,and a 2.68-mF capacitor.The circuit is driven by a rms emf of 110 V running at 60 Hz.What is the rms current in this circuit?

What is the current i in the circuit shown?

In a series RLC circuit,the voltages across the capacitor,resistor,and the inductor are V_c = 5.4 V,V_R = 7.5 V,and V_L = 11.2 V,respectively.Is the frequency of oscillations above,below,or equal to the resonant frequency of the circuit?

A series circuit contains a 240- $\varOmega$ resistor,a 3.8- $\mu$ F capacitor,and a 550-mH inductor.It is placed across the terminals of an ac generator with a frequency of f=100 Hz.If the rms current measured in the circuit is 353.5 mA,what is the rms voltage of the generator?

For the RLC circuit shown,which of the following statements is correct?

A simple tuned FM antenna circuit is used to pick up radio signals.The circuit is a series RLC circuit with an inductor (9.50 $\mu$ H)and a variable capacitor which can be tuned to receive your favorite station.The radio signal from your favorite FM radio station produces a sinusoidal time-varying emf with an amplitude 15 $\mu$ V and a frequency of 88.7 MHz in the antenna,which acts as an ac emf.Another radio station produces a sinusoidal time-varying emf with the same amplitude but with a frequency of 88.5 MHz.With the circuit tuned to optimize reception at 88.7 MHz,what should the value of the resistance in the FM circuit be in order to attenuate by a factor of two (compared to the power if the circuit were optimized for 88.5 MHz)the current produced by the signal from the second station?

An LC series circuit is comprised of a 10.0-mF capacitor in series with a 10.0-mH inductor.What is the period of electromagnetic oscillations in this circuit?

You are given three series RL circuits: circuit A has resistance R/2,inductance L;circuit B has resistance R,inductance L;and circuit C has resistance 2R and inductance L.Rank in order from smallest to largest quality factors,Q_A,Q_B, and Q_C for the resonant frequency 5 MHz.

What is the maximum current when a 33 nF capacitor is connected to a 240 V_rms,50-Hz power supply?

What is the angular frequency of the oscillation of a series RLC circuit with a resistance of 6 Ω,an inductance of 6 mH,and a capacitance of 6 µF?

Which of these statements are true about series RLC circuits: i.The instantaneous value of the current is the same everywhere in the circuit. ii.The voltage drop across the resistor is in phase with the current. iii.The voltage drop across the capacitor trails the current by 90 degrees. iv.The voltage drop across the inductance leads the current by 90 degrees.

Consider a series RLC circuit consisting of a 3.40- $\varOmega$ resistor,a 8.60-mH inductor,and a tunable capacitor.The circuit is driven by an rms emf of 110 V running at 60 Hz.What value of the capacitor will allow the strongest current amplitude oscillations to occur in the circuit?

An LRC circuit is running at it's resonance frequency with 250 volts rms what is the current through the resistor if R = 500 ohms,L = 60 H,and C = 0.2 micro-Farads?

An LRC oscillator circuit consists of a 50- $\varOmega$ resistor and a 1-mH inductor.What capacitance is necessary for the decay rate of the circuit (the 1/e value)to be equal to the oscillation period?

At what frequency in Hz is the current through the circuit shown a maximum?

An LC series circuit is comprised of a 1.0-mF capacitor in series with an inductor.The period of electromagnetic oscillations in this circuit is 100 ms.What is the inductance of the inductor?

An RLC series circuit is driven by an AC source consists of an inductor,capacitor and resistor having values of 1.5 mH,1.0 $\mu$ F,and 1.9 k $\varOmega$ ,respectively.At what frequency is the rms voltage across the resistor half the source rms voltage?

Consider a LC circuit with a 26.0-mH inductor and a 32.0- $\mu$ F capacitor.With a switch keeping the circuit open,the capacitor is charged with a charge of 21.0 $\mu$ C.At time t = 0 s the switch is closed,allowing charge to leave the capacitor.Calculate the first time when the energy stored in the capacitor equals the energy stored in the inductor.

The phase constant between the voltage and the current in an alternating current circuit depends on what parameters?