Power Factor and Phase Relationships in AC Circuits Quiz

Explore power factor concepts: resistance, inductive & capacitive circuits, efficiency, correction methods. Test your knowledge!

Practice Learn Test

What is the power factor of a purely resistive circuit?

-1

Depends on the resistance value

In an AC circuit, if the current and voltage are in phase, what is the power factor?

-1

Depends on the frequency

What is the unit of power factor?

Ohm

Siemens

Hertz

It is dimensionless

What is the range of power factor values in most practical AC circuits?

0 to 1

-1 to 1

-∞ to ∞

Depends on the circuit elements

What is the unit of reactive power?

Watt

Volt

Volt-Ampere Reactive (VAR)

Ampere

What is the formula for calculating power factor?

PF = P / V

PF = V / I

PF = cos(θ)

PF = V * I * cos(θ)

What does a leading power factor indicate?

Inductive circuit

Capacitive circuit

Resistive circuit

Mixed circuit

What happens to the power factor of a purely inductive circuit?

Increases

Decreases

Remains constant

Becomes negative

What is the relationship between power factor and energy efficiency in AC circuits?

Higher power factor leads to lower energy efficiency

Higher power factor leads to higher energy efficiency

Power factor does not affect energy efficiency

It depends on the frequency of the AC circuit

#10

What device is commonly used to improve power factor in AC circuits?

Transformer

Inductor

Capacitor

Diode

#11

In a circuit with a lagging power factor, the phase angle between current and voltage is...

Positive

Negative

Zero

Depends on the frequency

#12

What is the mathematical relationship between power factor and cosine of the phase angle?

PF = cos(θ)

PF = sin(θ)

PF = tan(θ)

PF = 1 / cos(θ)

#13

What is the cosine of the phase angle in a circuit with a power factor of 0.8?

0.8

0.6

0.64

0.5

#14

In a circuit with a power factor of 0.5, what is the relationship between real power and apparent power?

Real power is half of apparent power

Real power is double of apparent power

Real power is equal to apparent power

Real power is not related to apparent power

#15

What is the power factor of an ideal inductor?

-1

Depends on the inductance