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. Connecting wires
- B. An electrolyte present between them
- C. Electrodes themselves
- D. None of these
Explanation: The resistance present between the two electrodes of a cell is primarily due to the electrolyte present between them.
Correct answer: An electrolyte present between them- A. Less than its emf
- B. Greater than its emf
- C. Equal to emf
- D. None of these
Explanation: Electromotive force (emf): This is the maximum potential difference that a battery can provide when no current is flowing through it.
Correct answer: Greater than its emf- A. Power dissipation
- B. Energy dissipation
- C. Work
- D. None of these
Explanation: The loss of electrical energy per second is referred to as power dissipation.
Correct answer: Power dissipation304. The unit of emf is
- A. Newton
- B. Joule
- C. Ampere
- D. J/c
Explanation: Electromotive force (emf) represents the electrical potential difference or voltage provided by a source such as a battery or generator.
Correct answer: J/c- A. Energy
- B. Momentum
- C. Potential difference
- D. Current
Explanation: The potential difference (also known as voltage) between two points in an electric circuit is the amount of work done per unit charge in…
Correct answer: Potential difference- A. Charge
- B. Mass
- C. Energy
- D. None of these
Explanation: Kirchhoff's first rule is a manifestation of the law of conservation of electric charge, not the law of conservation of mass or energy.
Correct answer: Charge- A. Charge
- B. Mass
- C. Energy
- D. None of these
Explanation: Kirchhoff's second rule, or Kirchhoff's voltage law (KVL), states that the total voltage around any closed loop in a circuit must sum to…
Correct answer: Energy- A. Smaller
- B. Greater
- C. Zero
- D. None of these
Explanation: A voltmeter is connected in parallel to the component or portion of the circuit across which the potential difference is to be measured.
Correct answer: Zero- A. Ex = R/r x E
- B. Ex = E r/R
- C. Ex = I/L x E
- D. Both (b) and (c)
Explanation: Option (b) Ex = E r/R involves using the balancing length (r) and the total length of the potentiometer wire (R) to find the unknown emf…
Correct answer: Both (b) and (c)- A. Anode
- B. Cathode
- C. Electrode
- D. Electrolyte
Explanation: In electrochemical cells or batteries, the electrode connected to the positive terminal is called the anode.
Correct answer: Anode- A. Electrode
- B. Cathode
- C. Anode
- D. Electrolyte
Explanation: The electrode connected to the negative terminal of a battery or an electrochemical cell is called the cathode.
Correct answer: Cathode- A. One volt
- B. One ohm
- C. One ampere
- D. One coulomb
Explanation: Ohm (Ω) is the unit of electrical resistance. One ohm of resistance is defined as the resistance of a conductor through which a current of…
Correct answer: One ohm- A. Pot difference between its ends
- B. The nature of material
- C. Dimension
- D. The nature, dimension and physical state of conductor
Explanation: The resistance of a conductor depends on various factors, including:- The nature of the material: Different materials have different…
Correct answer: The nature, dimension and physical state of conductor- A. Remains the same
- B. Increase
- C. Decrease
- D. None of above
Explanation: When the resistance of a conductor increases while the potential difference across its ends remains constant, according to Ohm's Law, the…
Correct answer: Decrease315. The resistance of a conductor of length I.. cross-sectional area A and resistivity p is given by
- A. R = L/pA
- B. R = pL/A
- C. R = A/LA
- D. R = P/LA
Explanation: R = ρL/A is the correct expression for the resistance of the conductor based on its length, cross-sectional area, and resistivity.
Correct answer: R = pL/A316. The resistivity of the material having the resistance R, cross-sectional area A and length L is
- A. p = AL/R
- B. p = A/LR
- C. p = RA/L
- D. p = RL/A
Explanation: p = RA/L is the correct expression for the resistivity of the material based on its resistance, cross-sectional area, and length.
Correct answer: p = RA/L- A. Mass
- B. Length
- C. Cross-sectional area
- D. Resistivity
Explanation: The resistance of a conductor primarily depends on its length, cross-sectional area, and resistivity of the material.
Correct answer: Mass- A. Remains the same
- B. Always increase
- C. Always decrease
- D. None of these
Explanation: When the temperature of a conductor is raised, its resistance typically increases.
Correct answer: Always increase- A. Cross-sectional area
- B. Length
- C. Diameter
- D. None of these
Explanation: The resistance of a conductor is directly proportional to its length. When the length of a conductor increases, there is more material for…
Correct answer: Length- A. Remain unchanged
- B. Decreases
- C. Increases
- D. None of above
Explanation: When the temperature of a conductor increases, the thermal vibrations of atoms within the conductor increase as well.
Correct answer: Increases