Resistance, Inductance, and Capacitance Theory

How does increasing the dielectric thickness between capacitor plates affect capacitance (all else equal)?

It decreases capacitance and requires larger plate area to compensate

In a series AC circuit containing resistance and inductive reactance, how should the voltage drops across the resistor and inductor be combined to relate to the applied voltage?

Combine them as perpendicular components (vector/right-triangle relation)

According to Lenz's Law as summarized in the lesson, the induced effect in a circuit will:

Oppose the change in magnetic flux that produced it

In a series resistor-inductor circuit, how quickly does current approach its steady value after switch-on, as characterized in the lesson?

It reaches about 63% of its final value after one characteristic time interval

For a varactor (voltage-variable capacitor), what happens to capacitance as the reverse-bias voltage is increased?

It decreases

When a capacitor is first connected to a DC source and the switch is closed, how does the current in the external circuit behave over time?

It starts at a maximum and then decreases to zero

The lesson defines one coulomb of charge as approximately how many electrons?

About 6.28 × 10¹⁸ electrons

At the resonant frequency of a series circuit containing a capacitor and inductor, what is the overall effect described in the lesson?

Opposing reactive effects cancel, leaving mainly resistance and allowing high current

About how long does it take a charging capacitor to reach essentially full charge as described in the lesson?

Roughly five time constants

When inductors are connected in series, how is the total inductance determined?

It equals the sum of the individual inductances

With capacitance held constant, increasing the AC frequency has what qualitative effect on a capacitor's opposition to current?

It decreases the opposition

In a parallel capacitor network, which quantity is the same across all branches?

Voltage

Which smaller units of capacitance are commonly used in practice according to the lesson?

Microfarad and picofarad

Which change increases the capacitance of a parallel-plate capacitor, all else equal?

Doubling plate area

Holding other factors constant, what is the effect of doubling the number of turns in a coil?

It roughly quadruples the inductance

What is true about total capacitance when capacitors are placed in series?

It is less than the smallest individual capacitance

In a purely capacitive AC circuit, how do current and voltage relate in time?

Current leads the voltage by a quarter cycle

With the same resistor, if the applied voltage is doubled, what happens to current according to the lesson?

It doubles

If an alternating voltage has an effective value of 500 volts, what working voltage should be selected for the capacitor per the lesson's guidance?

At least about 750 V

In a resistor-capacitor circuit, about what fraction of the source voltage does the capacitor reach after one "time constant"?

About 63%

In the lesson's discussion of current voltage plots, when does the relationship appear as a straight line?

When the circuit resistance remains constant

Which statement best describes how a good capacitor treats steady DC and alternating or pulsing signals?

It blocks steady DC but passes the effects of pulsing DC or AC

Variable capacitors are used primarily for what application in the lesson?

Radio tuning circuits

A 220-volt AC motor draws 50 amperes, and a wattmeter reads 9,350 watts. Which power factor matches the lesson's example?

85%

After charging a capacitor from a DC source and opening the switch, what do the plates do according to the lesson?

They remain charged