Free Alternating Current MCQs with Answers
592 Alternating Current 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 varies periodically, so phase relationships become essential when current passes through a resistor, capacitor or inductor. The chapter distinguishes resistance from capacitive and inductive reactance, explains phase lead and lag, and connects changing electric and magnetic fields with the production and properties of electromagnetic waves.
Last updated
Read the Alternating Current notesFree MDCAT chapter notes with key terms592 questions · page 24 of 30
- A. 2 x 10^6
- B. 3 x 10^6
- C. 4 x 10^6
- D. 6 x 10^6
Explanation: d = √(2Rh)where:• d = maximum distance covered by the tower• R = radius of the Earth = 6.4 * 10 ^ 6 m• h = height of the tower = 100mStep…
Correct answer: 4 x 10^6- A. Newton
- B. Maxwell
- C. Hertz
- D. Huygen
Explanation: The existence of electromagnetic waves was theoretically predicted by Maxwell.
Correct answer: Maxwell- A. V0=1.414 Vrms
- B. Irms=1.414 Io
- C. V0=10.70 Vrms
- D. Both A and B
Explanation: This statement is correct. V0 represents the peak value of an alternating voltage, while Vrms represents the root mean square (RMS) value…
Correct answer: V0=1.414 Vrms- A. Increases
- B. Decreases
- C. Remains the same
- D. Increases only when the voltage increases
Explanation: This is the correct answer. At higher frequencies, capacitive reactance decreases.
Correct answer: Decreases- A. Lags behind the voltage by 90o or π/2
- B. Leads the voltage by 90o or π/2
- C. Lags behind the voltage by 180o or π
- D. Is in phase with the voltage
Explanation: This is the correct answer. In an inductive A.C circuit, the current lags behind the voltage by 90 degrees (π/2 radians) in phase.
Correct answer: Lags behind the voltage by 90o or π/2- A. 60o
- B. 45o
- C. 30o
- D. 90o
Explanation: This is the correct answer. In an alternating current waveform, the r.m.s value is equal to the maximum value of the current when the…
Correct answer: 45o- A. 0o
- B. 90o
- C. 180o
- D. 270o
Explanation: This is the correct answer. At resonance in an RLC series circuit, the inductive reactance (XL) and capacitive reactance (XC) are equal in…
Correct answer: 0o- A. R
- B. XL
- C. XC
- D. None of the above
Explanation: This is the correct answer. At resonance in an RLC series circuit, the impedance is primarily resistive and is equal to the resistance (R)…
Correct answer: R- A. 0o
- B. 90o
- C. 180o
- D. 45o
Explanation: When the resistance (R) in a series RC circuit is equal to the capacitive reactance (XC'), it results in a special condition where the…
Correct answer: 45o- A. IC/IB
- B. IC/IE
- C. IE/IB
- D. IB/IE
Explanation: This is the correct answer. The current gain (β) for a common-emitter configuration of an n-p-n transistor is defined as the ratio of the…
Correct answer: IC/IB- A. Reverses
- B. Increases
- C. Decreases
- D. Stops
Explanation: This is the correct answer. The current gain (β) for a common-emitter configuration of an n-p-n transistor is defined as the ratio of the…
Correct answer: Decreases- A. AOL=V0/Vi
- B. AOL=V0 x Vi
- C. AOL= Vi/V0
- D. None of these
Explanation: This is the correct answer. In an open-loop configuration, the open-loop gain (AOL) of an op-amp is defined as the ratio of the output…
Correct answer: AOL=V0/Vi- A. Both inputs are 0
- B. Either input is 1
- C. Both inputs are 1
- D. Either input is 0
Explanation: This is the correct answer. In an OR gate, the output is 0 only when both of its inputs are 0.
Correct answer: Both inputs are 0- A. High
- B. Low
- C. Different
- D. Same
Explanation: This is the correct answer. An XOR gate is designed to produce an output when its two inputs are different.
Correct answer: Different- A. ON
- B. Positive
- C. High
- D. OFF
Explanation: This is the correct answer. A NOR gate is ON, meaning it produces an output of 1, when its inputs are both LOW (0).
Correct answer: OFF- A. NAND
- B. NOR gate
- C. XOR gate
- D. NOT gate
Explanation: This is the correct answer. The expression X = AB + AB represents a XOR gate.
Correct answer: XOR gate- A. NAND gate
- B. NOR gate
- C. OR gate
- D. NOT gate
Explanation: This is the correct answer. The given Boolean expression X = A + B represents the logical OR operation.
Correct answer: OR gate- A. 100 Hz
- B. 200 Hz
- C. 400 Hz
- D. 800 Hz
Explanation: The given expression for the alternating current is I = 4 sin(200πt), where the angular frequency ω is 200π.
Correct answer: 100 Hz- A. Low pass filter
- B. High pass filter
- C. Both a and b
- D. None
Explanation: A capacitor is commonly used in electronic circuits as a high pass filter.
Correct answer: High pass filter- A. 100 watt
- B. 200 watt
- C. 282.84 watt
- D. None
Explanation: In AC systems, the RMS values are used to express power similar to DC systems.
Correct answer: 200 watt