Rlc Circuits

A resistor is connected to an AC power supply. The current in this circuit ____

• Leads the voltage by 90

• Lags the voltage by 45°

• Lags the voltage by 90°

• in phase with the voltage

In an AC series circuit, the current in a pure resistor differs in phase with the applied voltage by what angle?

• 0°

• 45°

• 90°

• 80°

The voltage output of an AC source is given by the expression ∆v = 200 sin wt, where ∆v is in volts. What is the rms current in the circuit when this source is connected to a 100 ohms resistor.

• 300 A

• 2.82 A

• 2.0 A

• 1.41 A

Which of the following statements can be true for a resistor connected in a simple series circuit to an operating AC generator?

I. The average power dissipated in the resistor is positive

II. The average power dissipated in the resistor is zero

III. The average current is zero

• I only

• II only

• III only

• I and III only

In an AC series circuit, the current in a pure capacitor differs in phase with the applied voltage by what angle

• 0°

• 45°

• 90°

• 180°

The graph below represents an AC circuit that consists of a generator and a capacitor. The voltage __________.

• lags the current by 45°

• lags the current by 90°

• leads the current by 45°

• leads the current by 90°

As the frequency of the AC voltage across a capacitor approaches zero, the capacitive reactance of that capacitor _______.

• approaches zero

• approaches infinity

• becomes negative

• does not change

Which of the following statements about capacitive reactance is true?

• It is independent of capacitance

• It is very small at low frequencies

• decreases with increasing capacitance

• increases with increasing capacitance

The graph below represents an AC circuit that consists of a generator and an inductor. The voltage __________.

• lags the current by 45°

• lags the current by 90°

• leads the current by 45°

• leads the current by 90°

An inductor and a resistor are connected in series across an AC generator, as shown below. Immediately after the switch is closed, which of the following statements is true?

• The current in the circuit is ∆V/R

• The current in the circuit is zero

• The voltage across the inductor is zero

• The voltage across the inductor is ∆V/2