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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461. The change in potential energy per unit charge between two points in an electric field is called
- A. Potential difference
- B. Absolute Potential
- C. Electric intensity
- D. Permittivity
Explanation: The difference in electric potential energy of a unit charge between two points within the electric field is called electric potential…
Correct answer: Potential difference- A. Changing
- B. Absolute zero
- C. Constant
- D. None of these options is correct
Explanation: It is factual that for Ohm's law to be applicable, the temperature has to be constant.
Correct answer: Constant- A. Increases with increase in its internal resistance
- B. Decreases with increase in internal resistance
- C. Is independent of its internal resistance
- D. None of these options is correct
Explanation: The internal resistance of a battery is defined as the opposition to the flow of current within the battery which means an increase in…
Correct answer: Decreases with increase in internal resistance- A. Supply of electrical energy by battery
- B. production of electrical energy of a battery
- C. both
- D. none of these
Explanation: According to the law of consercation of energy, energy cannot be created or destroyed, option B and C are wrong.
Correct answer: Supply of electrical energy by battery- A. VI
- B. I^2 R
- C. V^2 / R
- D. all
Explanation: Electrical power has 3 formulas which are P= IV, P= I^R and P= V^2 / R
Correct answer: all- A. Law of conservation of energy
- B. Law Of conservation Of momentum
- C. Law of conservation of charge
- D. Law of conservation of mass
Explanation: Kirchhoff's first law states that the algebraic sum of current flowing into a junction is zero.
Correct answer: Law of conservation of charge- A. 4R
- B. 3R
- C. 2R
- D. R
Explanation: The correct answer is 2R. To understand why, we first consider that when the length of the wire is halved, the resistance is halved as…
Correct answer: 2R- A. 2.2 W
- B. 2.2 kW
- C. 22 kW
- D. 22 W
Explanation: Power = Voltage x Current; 220 x 0.1 = 22W
Correct answer: 22 W- A. Changing
- B. Constant
- C. All of These
- D. None of these
Explanation: Ohm's Law states that the current flowing through a conductor is directly proportional to the voltage across it, provided the temperature…
Correct answer: Changing- A. Increases
- B. Decreases
- C. Remains same
- D. None of the above
Explanation: In a lamp load where more than one lamp is switched on, the total resistance of the load decreases.
Correct answer: Decreases- A. 1
- B. 0.1
- C. 0.01
- D. None of these
Explanation: The internal resistance (r) of a battery can be calculated using Ohm's law.
Correct answer: 1- A. Ohm
- B. Ampere
- C. Watt
- D. Volts
Explanation: Ohm is the SI unit for Resistance. Ampere is the SI unit for Current. Watt is the SI unit for Power.
Correct answer: Ohm473. Electric power is?
- A. Rate of electric work done per unit time
- B. Voltage per unit time
- C. Electric charge per unit time
- D. Current per unit time
Explanation: Electric power is defined as the rate at which work is done or energy is transferred in an electric circuit.
Correct answer: Rate of electric work done per unit time- A. Very low
- B. Very high
- C. Varying
- D. Constant
Explanation: Option A) Very low is incorrect because the temperature coefficient of resistance for most conductors is positive, which means that their…
Correct answer: Constant- A. Circuit is closed
- B. Current is maximum
- C. Circuit is open
- D. All of these options are correct
Explanation: The EMF (electromotive force) represents the potential difference across the terminals of a battery when no current is flowing.
Correct answer: Circuit is open- A. Diode
- B. Tungsten wire
- C. Carbon resistor
- D. Copper wire
Explanation: Diodes are examples of non-ohmic resistors because they do not have a constant resistance and their current-voltage relationship is…
Correct answer: Diode- A. 1.6 Ohms
- B. 1.5 Ohms
- C. 1.7 Ohms
- D. 1.8 Ohms
Explanation: We know that V = IRRearranging this formula gives:R= VI= 45/30= 312= 1.5 OhmsAs it is numerical so it can have only one possible answer.
Correct answer: 1.5 Ohms- A. Conductor
- B. Source
- C. Time
- D. Potential difference
Explanation: Option A) Conductor, is not the correct answer because the amount of current flowing through a conductor can vary depending on its…
Correct answer: Time479. Galvanometer is an?
- A. Electromechanical device
- B. Electrosolar device
- C. Electrothermal device
- D. None of these options is correct
Explanation: Option A) A galvanometer is an electromechanical measuring instrument for electric current.
Correct answer: Electromechanical device- A. Non-linear
- B. Varying
- C. Linear
- D. None of these options are correct
Explanation: Ohm's law defines the relationship between the voltage, current, and resistance in an electric circuit: I = V/R.
Correct answer: Linear