Free AC Through Resistor, Capacitor and Inductor MCQs with Answers
76 AC Through Resistor, Capacitor and Inductor MCQs from Physics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Alternating current through a resistor, capacitor and inductor involves phase relationships between voltage and current, reactance, impedance and energy transfer. A resistor keeps voltage and current in phase, while a capacitor and inductor produce opposite phase shifts, a distinction used in circuit diagrams and numerical calculations.
Last updated
76 questions · page 3 of 4
- A. 7A
- B. 49A
- C. 7√2A
- D. 254A
Explanation: The mean square value (or RMS value) of an alternating current (AC) is given by the peak value divided by the square root of 2.Given that…
Correct answer: 7A- A. Current leads the voltage in a phase
- B. Current lags behind the voltage in a phase
- C. Current and voltage are in same phase
- D. Depends upon resistance
Explanation: Here is the explanation of the correct option Current and voltage vary sinusoidal with same frequency and are in phase with each other
Correct answer: Current and voltage are in same phase- A. zero.
- B. large.
- C. small.
- D. undetermined.
Explanation: at high frequencies, Xc becomes very small, allowing a large current to flow through the capacitor.
Correct answer: large.- A. 2 L I2
- B. 4 L I2
- C. 8 L I2
- D. 16 L I2
Explanation: The energy stored in an inductor is given by the formula E = 1/2 L I2. When the current 'I' increases by a factor of 4, the new energy…
Correct answer: 16 L I2- A. inductor
- B. capacitor
- C. impedance
- D. modulation
Explanation: The correct answer is 'impedance.' In a circuit, impedance is the combination of resistance (which opposes the flow of current) and…
Correct answer: impedance- A. Zero
- B. Large
- C. Small
- D. Varying unpredictably
Explanation: In an alternating current circuit, the current through a capacitor increases with frequency because the capacitive reactance (which…
Correct answer: Large- A. 314.2 V
- B. 220.0 V
- C. 154.0 V
- D. 110.0 V
Explanation: The correct answer is Option A: 314.2 V. The peak value of an AC voltage is √2 times the RMS value.
Correct answer: 314.2 V- A. I and II
- B. I and IV
- C. II and III
- D. III and IV
Explanation: The correct answer is Option C: II and III. In alternating current (AC) circuits, inductors store energy in magnetic fields, and…
Correct answer: II and III- A. Io
- B. √2 Io
- C. Io / √2
- D. 2 Io
Explanation: The correct formula for finding the root mean square (r.m.s.) current for an alternating current (AC) signal is Io / √2, as indicated in…
Correct answer: Io / √2- A. Resistor
- B. Inductor
- C. Capacitor
- D. Transistor
Explanation: The correct answer is Transistor. Transistors are primarily used for amplification and switching purposes rather than directly controlling…
Correct answer: Transistor- A. Zero.
- B. Large.
- C. Small.
- D. Undetermined.
Explanation: In an AC circuit, the current through a capacitor depends on the capacitive reactance, which is inversely proportional to the frequency.
Correct answer: Large.- A. Option A: The vectors for IC and IR are in phase.
- B. Option B: The vector for IC leads the vector for IR by 90 degrees.
- C. Option C: The vectors for IC and IR are out of phase by 180 degrees.
- D. Option D: The vectors for IC and IR are perpendicular.
Explanation: In an RC circuit, the current through the capacitor (IC) leads the current through the resistor (IR) by 90 degrees due to the capacitive…
Correct answer: Option B: The vector for IC leads the vector for IR by 90 degrees.- A. Resistance.
- B. Impedance.
- C. Capacitance.
- D. Conductance.
Explanation: The correct answer is impedance. In an alternating current (AC) circuit, impedance is the term used to describe the ratio of the root mean…
Correct answer: Impedance.- A. Zero.
- B. More.
- C. Less.
- D. Infinite.
Explanation: Capacitive reactance (XC) is given by the formula XC = 1/(2πfC), where f is the frequency and C is the capacitance.
Correct answer: Zero.- A. The current will be zero.
- B. The current will be large.
- C. The current will be small.
- D. The current will be undetermined.
Explanation: In an AC circuit, a capacitor's reactance decreases as the frequency increases.
Correct answer: The current will be large.- A. Proportional to (frequency)2
- B. Proportional to frequency
- C. Proportional to (frequency)½
- D. Independent to frequency
Explanation: a) Proportional to (frequency)^2:The rate of production of heat in a pure resistor, when connected to an alternating potential difference…
Correct answer: Proportional to (frequency)2- A. 2.2mA
- B. 2.2/√2 mA
- C. 2.2 x √2 mA
- D. None of the above
Explanation: By Ohm's law; V=IRIrms = Vrms/R = 220/100x10(3) = 2.2x10(-3) A= 2.2mA
Correct answer: 2.2mA- A. Resonance
- B. Resistance.
- C. Current.
- D. None of these.
Explanation: When the frequency of the transmitted wave matches the one displayed on the radio, which is done by tuning it, the amplitude of the sound…
Correct answer: Resonance- A. R is large, L is very small
- B. R is very small, L is large
- C. Both R and L are large
- D. Both R and L are very small
Explanation: In an ideal choke, a coil should have almost zero internal resistance, R≈0, if a coil has resistance it will consume power.Since R needs…
Correct answer: R is very small, L is large- A. Capacitance
- B. Inductance
- C. Charge
- D. Resistance
Explanation: The correct answer is Inductance. In the context of electrical systems, inductance is analogous to mass because both properties determine…
Correct answer: Inductance