Free Current Electricity MCQs with Answers
1,052 Current Electricity MCQs from Physics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Steady current relates charge flow to potential difference, resistance and resistivity, including how temperature changes a conductor's resistance. Sources with internal resistance have terminal voltage below their emf when delivering current, and maximum power output occurs under a specific load condition rather than at zero resistance.
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- A. Reactance of generator
- B. Input torque
- C. Losses
- D. Reactance of transmission line
Explanation: System stability refers to the ability of a system to maintain its equilibrium or desired state of operation despite disturbances.
Correct answer: Losses- A. Zero resistance
- B. Load resistance
- C. Max resistance
- D. None of these
Explanation: The maximum power is delivered when the internal resistance of the source equals the load resistance.This is known as the maximum power…
Correct answer: Load resistance- A. Rate of flow of charge
- B. Rate of flow of momentum
- C. Rate of flow of power
- D. None of these options is correct
Explanation: Electricity is the flow of electrons, also called charges which can be denoted by "Q".
Correct answer: Rate of flow of charge- A. Coulomb
- B. Ampere
- C. Hertz
- D. Volt
Explanation: OPTION A: This is a fact to be memorized. The SI unit for electric charge is Coulomb.OPTION B: Ampere is the unit of electric current, not…
Correct answer: Coulomb- A. Power is proportional to voltage only
- B. Power is proportional to current only
- C. Power is neither proportional to voltage nor to the current
- D. Power is proportional to both voltage and the current
Explanation: The correct answer is that power is proportional to both voltage and the current.
Correct answer: Power is proportional to both voltage and the current- A. 6.4 a, 6.9 a
- B. 6.4 a, 9.6 a
- C. 4.6 a, 6.9 a
- D. 4.6 a, 9.6 a
Explanation: To calculate the current in each branch, we first need to calculate the total resistance of the circuit.
Correct answer: 6.4 a, 9.6 a- A. l = VR
- B. R = VI
- C. I = R/V
- D. I = V/R
Explanation: OHM'S LAW STATEMENT: The magnitude of the current in a conductor is proportional to the applied voltage as long as the temperature of the…
Correct answer: I = V/R- A. Resistor
- B. Super-conductor
- C. Thermocouple
- D. Thermistor
Explanation: OPTION A:A resistor is an electrical component that limits or regulates the flow of electrical current in an electronic circuit.OPTION B:A…
Correct answer: Thermistor- A. Doubles
- B. Halves
- C. Remains the same
- D. Increases three times
Explanation: The resistivity is dependent on the material. If the length and/or the cross-sectional area change, it does not affect the resistivity.
Correct answer: Remains the same- A. (Amperes)2 ohm
- B. Joules/sec
- C. Amperes x volts
- D. Amperes/volt
Explanation: Power = V x I.and Power SI Unit = Watt.and watt = "volt x ampere".Hence, Option D is impossible.
Correct answer: Amperes/volt- A. Electrical energy consumed by the battery
- B. Electrical energy transferred by the battery
- C. Both Options A and B are correct
- D. None of these options is correct
Explanation: AC current changes its direction periodically due to which, in a complete cycle, electrical energy is transferred to the apparatus and…
Correct answer: Both Options A and B are correct532. If 1 A current flows through a 2 m long conductor, the charge flowing through it in 1 hour will be?
- A. 3600 C
- B. 7200 C
- C. 1 C
- D. 2 C
Explanation: Current is the rate of flow of electrons.Current = charge / time.I = Q/t.Since 1 hour has 3600 seconds,1 = Q/3600.Q = "3600 C".
Correct answer: 3600 C533. A resistance of 40 Ohms is attached to a circuit having a current of 300 Amperes. Find its voltage.
- A. 12000 volts.
- B. 15000 volts
- C. 20000 volts
- D. 300 volts
Explanation: Using the Ohm's Law; V = IR. R = 40. I = 300. V = 40x300. V = "12000 volts".
Correct answer: 12000 volts.- A. 5 KJ
- B. l0 KJ
- C. 15 KJ
- D. 20 KJ
Explanation: I=5AR=2 ohmst=300 sE=?As, power P=I2RP=522P=252P= 50 WAlso, P=Energy/timeenergy = power X timeenergy = 50300energy =15,000J energy = 15kJ
Correct answer: 15 KJ- A. Same
- B. Different
- C. Sometimes same sometimes different
- D. None of these options is correct
Explanation: Current is the same in each device since there is only a single pathway for the charge to flow.
Correct answer: Same- A. Same current
- B. Same current and a potential difference
- C. Different current but the same potential difference
- D. Different current and potential differences
Explanation: A parallel circuit comprises branches so that the current divides and only part of it flows through any branch.
Correct answer: Different current but the same potential difference- A. Semiconductor
- B. Metal
- C. Non-metal
- D. Organic compound
Explanation: Semiconductors are materials which have a conductivity between conductors (generally metals) and nonconductors or insulators (such as most…
Correct answer: Semiconductor538. PD stands for:
- A. Potential difference
- B. Potential deviation
- C. Power difference
- D. Power dissipated
Explanation: Potential difference is the difference in the amount of energy that charge carriers have between two points in a circuit.
Correct answer: Potential difference- A. Temperature of the material is decreased
- B. Temperature of the material is increased
- C. Number of free electrons available becomes more
- D. None of the above options is correct
Explanation: The correct answer is option B: Temperature of the material is increased.
Correct answer: Temperature of the material is increased- A. 50 W
- B. 75 W
- C. 100 W
- D. 90 W
Explanation: Power = voltage x current P= 250 x 0.3 P= 75 W (option B)
Correct answer: 75 W