Capacitor Reactance and Behavior

The video tutorial explores the behavior of capacitors in AC circuits, contrasting them with resistors and inductors. It explains how capacitors behave differently in AC circuits, focusing on the flow of charge and the sinusoidal nature of current. The tutorial discusses the phase difference between voltage and current in capacitors, highlighting that the voltage leads the current by 90 degrees. It also covers the concept of reactance in capacitors, explaining how it varies with frequency and capacitance. The tutorial concludes by emphasizing the importance of understanding these concepts for analyzing AC circuits.

What is the primary difference in behavior between capacitors and resistors in AC circuits?

• Capacitors do not affect AC circuits.

• Capacitors store energy, resistors do not.

• Capacitors behave the same as resistors in AC circuits.

• Capacitors have a constant voltage drop, resistors do not.

How does the current behave in a capacitor within an AC circuit?

• It does not flow at all.

• It flows sinusoidally.

• It flows in one direction only.

• It remains constant.

In a capacitor, how is the voltage drop related to the current?

• Voltage drop lags the current by 90 degrees.

• Voltage drop is opposite to the current.

• Voltage drop leads the current by 90 degrees.

• Voltage drop is in phase with the current.

What is the term used to describe the opposition to current flow in a capacitor?

• Resistance

• Inductance

• Reactance

• Impedance

How does the reactance of a capacitor change with frequency?

• It increases with increasing frequency.

• It becomes zero at high frequencies.

• It decreases with increasing frequency.

• It remains constant regardless of frequency.

What happens to the reactance of a capacitor if the capacitance is very large?

• It acts more like a wire.

• It acts more like a resistor.

• It acts more like an inductor.

• It acts more like an open circuit.

What is the mathematical expression for the reactance of a capacitor?

• Xc = C / omega

• Xc = omega / C

• Xc = 1 / (omega * C)

• Xc = omega * C

If the capacitance is very small, how does the capacitor behave?

• Like a short circuit

• Like a resistor

• Like an inductor

• Like an open circuit

What is the unit of reactance in a capacitor?

• Farads

• Ohms

• Volts

• Henrys

What happens to the reactance of a capacitor as the frequency approaches zero?

• It becomes negative.

• It becomes infinite.

• It becomes zero.

• It remains constant.