physics : class12 Difference Between Wattful and Wattless Current : Wattless Current : Electromagnetic Induction and Alternating Currents MCQ Questions and Answers
Practice important
Difference Between Wattful and Wattless Current
MCQ questions and answers.
Page 1
of
1
|
10
MCQ Questions
1. What is meant by wattful current in an AC circuit?
A.
The component of current that consumes average power
B.
The component of current that consumes no power
C.
The current that always leads voltage by 90 degrees
D.
The current that always lags voltage by 90 degrees
Correct Answer:
The component of current that consumes average power
Explanation:
Wattful current is the in-phase component of current and contributes to the average or real power consumed by the circuit.
2. What is meant by wattless current in an AC circuit?
A.
The current that consumes maximum average power
B.
The component of current that consumes no average power
C.
The current that is always in phase with voltage
D.
The current that has zero instantaneous value
Correct Answer:
The component of current that consumes no average power
Explanation:
Wattless current is the component of current that does not consume average power because it is in quadrature with the voltage.
3. In a purely resistive AC circuit, the current is mainly classified as
A.
Wattless current
B.
Wattful current
C.
Zero current
D.
Opposing current
Correct Answer:
Wattful current
Explanation:
In a purely resistive circuit, current and voltage are in phase, so the current contributes to real power and is wattful.
4. In a purely inductive AC circuit, the current is classified as
A.
Wattful current
B.
Wattless current
C.
Direct current
D.
Constant current
Correct Answer:
Wattless current
Explanation:
In a purely inductive circuit, current lags voltage by 90 degrees, so its average power consumption is zero and it is wattless.
5. What is the phase difference between voltage and wattless current in an ideal AC circuit?
A.
0 degrees
B.
45 degrees
C.
90 degrees
D.
180 degrees
Correct Answer:
90 degrees
Explanation:
Wattless current is perpendicular in phase to the voltage, giving a phase difference of 90 degrees and zero average power.
6. Which current contributes directly to the average power consumed in an AC circuit?
A.
Wattless current
B.
Wattful current
C.
Induced current only
D.
Charging current only
Correct Answer:
Wattful current
Explanation:
Only the wattful, or in-phase, component of current contributes directly to the average power consumed by the circuit.
7. The average power consumed by a purely wattless current is
A.
Zero
B.
Equal to the maximum power
C.
Half of the maximum power
D.
Always negative
Correct Answer:
Zero
Explanation:
A wattless current differs in phase from voltage by 90 degrees, making its average power consumption zero.
8. Which statement correctly distinguishes wattful current from wattless current?
A.
Wattful current consumes average power, while wattless current does not
B.
Both currents always consume the same average power
C.
Wattful current has a 90-degree phase difference, while wattless current is in phase
D.
Wattless current is found only in a purely resistive circuit
Correct Answer:
Wattful current consumes average power, while wattless current does not
Explanation:
Wattful current is in phase with voltage and consumes real power, whereas wattless current is in quadrature and consumes no average power.
9. If the current and voltage in an AC circuit are in phase, the current is
A.
Wattless
B.
Wattful
C.
Always zero
D.
Unrelated to power
Correct Answer:
Wattful
Explanation:
An in-phase current has a phase difference of zero with the voltage and therefore contributes fully to average power.
10. Which type of current is associated with energy that is alternately stored and returned by an ideal inductor or capacitor?
A.
Wattful current
B.
Wattless current
C.
Steady direct current
D.
Short-circuit current
Correct Answer:
Wattless current
Explanation:
In an ideal inductor or capacitor, energy is stored and returned during each cycle, so the current is wattless and consumes no average power.
Short Questions and Answers
Practice short questions and answers related to
Difference Between Wattful and Wattless Current
.
Short questions are currently unavailable for this page.