Exam 31: Electromagnetic Oscillations and Alternating Current

A generator supplies 100 V to the primary coil of a transformer.The primary has 50 turns and the secondary has 500 turns.The secondary voltage is:

An RLC circuit has a sinusoidal source of emf.The average rate at which the source supplies energy is 5 nW.This must also be:

An ac generator producing 10 V (rms)at 200 rad/s is connected in series with a 50- $\Omega$ resistor, a 400-mH inductor, and a 200- $\mu$ F capacitor.The rms current is:

An ac generator producing 10 V (rms)at 200 rad/s is connected in series with a 50- $\Omega$ resistor, a 400-mH inductor, and a 200- $\mu$ F capacitor.The rms voltage across the resistor is:

An ac generator producing 10 V (rms)at 200 rad/s is connected in series with a 50- $\Omega$ resistor, a 400-mH inductor, and a 200- $\mu$ F capacitor.The rms voltage across the inductor is:

The impedance of the circuit shown is:

At time t = 0 the charge on the 50- $\mu$ F capacitor in an LC circuit is 15 $\mu$ C and there is no current.If the inductance is 20 mH the maximum current is:

A 150-g block on the end of a spring with a spring constant of 35 N/m is pulled aside 25 cm and released from rest.In the electrical analog the maximum charge on the capacitor is 0.25 C.The maximum current in the LC circuit is:

An electric motor, under load, has an effective resistance of 30 $\Omega$ and an inductive reactance of 40 $\Omega$ .When powered by a source with a maximum voltage of 420 V, the maximum current is:

An LC circuit has a capacitance of 30 $\mu$ F and an inductance of 15 mH.At time t = 0 the charge on the capacitor is 10 $\mu$ C and the current is 20 mA.The maximum current is:

A series RL circuit is connected to an emf source of angular frequency $\omega$ .The current:

An LC series circuit with an inductance L and a capacitance C has an oscillation frequency f.If we now take two of those inductors, each with inductance L, and two of the capacitors, each with capacitance C, and wire them all in series to make a new circuit, its oscillation frequency will be:

An RLC series circuit is driven by a sinusoidal emf with angular frequency $\omega$ _d.If $\omega$ _d is increased without changing the amplitude of the emf, the current amplitude increases.If L is the inductance, C is the capacitance, and R is the resistance, this means that:

In a sinusoidally driven series RLC circuit, the inductive resistance is X_L = 200 $\Omega$ , the capacitive reactance is X_C = 100 $\Omega$ , and the resistance is R = 50 $\Omega$ .The current and applied emf would be in phase if:

In an RLC series circuit, which is connected to a source of emf _mcos( $\omega$ t), the current lags the voltage by 45 $\degree$ if:

A charged capacitor and an inductor are connected in series.At time t = 0 the current is zero, but the capacitor is charged.If T is the period of the resulting oscillations, the next time, after t = 0 that the voltage across the inductor is a maximum is:

The impedance of an RLC series circuit is definitely increased if:

In order to maximize the rate at which energy is supplied to a resistive load, the power factor of an RLC circuit should be as close as possible to:

An LC circuit has an inductance of 20 mH and a capacitance of 5.0 $\mu$ F.If the charge amplitude is 40 F $\mu$ C, what is the current amplitude?

A 35- $\mu$ F capacitor is connected to an ac source of emf with a frequency of 400 Hz and a maximum emf of 20 V.The maximum current is: