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.
Last updated
1,052 questions · page 38 of 53
- A. 0V
- B. 6.0 V
- C. 2.6 V
- D. 5.2 V
Explanation: With an open circuit, the potential difference across the switch is the same as the battery's emf.This is the correct answer.
Correct answer: 6.0 V- A. Chemical
- B. Mechanical
- C. Nuclear
- D. Thermal
Explanation: Meters use electromagnetic forces to move pointers or displays.This is the correct answer.
Correct answer: Mechanical- A. Decreasing
- B. Increasing
- C. Constant
- D. Alternating
Explanation: Back EMF opposes current change, so a decreasing current causes opposition.This is the correct answer.
Correct answer: Decreasing- A. Current
- B. Voltage
- C. Motion of charges
- D. Opposition to the motion of charges
Explanation: Correct. Resistance is defined as the opposition to the flow of electric charges in a conductor.
Correct answer: Opposition to the motion of charges- A. Decreases with rise in temperature
- B. Increases with rise in temperature
- C. Decreases with a fall in temperature
- D. Does not change with a change in temperature
Explanation: Decreases with rise in temperature - Correct: The internal resistance of a battery decreases as temperature increases, allowing more…
Correct answer: Decreases with rise in temperature- A. Length
- B. Area of cross-section
- C. Shape
- D. Material
Explanation: Material - Correct: Resistivity is a fundamental property of a material and varies for different substances, regardless of shape, length…
Correct answer: Material- A. R/n4
- B. R/n2
- C. R/n
- D. Nr
Explanation: Correct. Let's derive the new resistance.Original Resistance:R = ρL/A, where ρ is resistivity, L is length, and A is cross-sectional area…
Correct answer: R/n4- A. Law of conservation of momentum
- B. Law of conservation mass
- C. Law of conservation of energy
- D. Law of conservation of charge
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. Temperature coefficient of resistance
- B. Thermal coefficient
- C. Linear coefficient of expansion
- D. Volumetric coefficient of expansion
Explanation: The fractional change in resistance per kelvin is called the temperature coefficient.
Correct answer: Temperature coefficient of resistance- A. 1.5 x 10^19 electrons
- B. 2.75 x 10^19 electrons
- C. 3.25 x 10^19 electrons
- D. 2.75 x 10^15 electrons
- E. 3.25 x 10^17 electrons
Explanation: I=4.4A e=1.610-19C (charge on one electron)t=1sn=? (no of electrons)Solution: I=q/t As, q=ne I=ne/tRearranging n=(It)e n=(4.41)1.610-19C…
Correct answer: 2.75 x 10^19 electrons- A. 1200 Coulombs
- B. 600 Coulombs
- C. 500 Coulombs
- D. 20 Coulombs
Explanation: This is straightforward CalculationI = Q/t ;Q = ItI = 2.0 Ampt = 10 Minutes = 10 x 60 = 600 secsQ = 2.0 x 600 = 1200 C
Correct answer: 1200 Coulombs- A. Conductivity
- B. Resistivity
- C. Resistance
- D. Inductance
Explanation: Reciprocal of conductance is resistance.
Correct answer: Resistance- A. 1.0A
- B. 2.5A
- C. 3.0A
- D. 4.0A
Explanation: In parallel arrangement, each resistor provides an alternate path to the current between the end points which means that current I is…
Correct answer: 4.0A- A. Circuit is closed
- B. Current is max
- C. Circuit is open
- D. All of these options are correct
Explanation: EMF is equal to the terminal potential difference when no current flows i.e. the circuit is open.
Correct answer: Circuit is open- A. Semiconductor
- B. Vacuum tubes
- C. Carbon resistors
- D. None of these
Explanation: Correct option is D. Ohm's law states that: at a constant temperature, the current through a conductor between two points is directly…
Correct answer: None of these- A. Resistance will be doubled and specific resistance will be halved
- B. Resistance will be halved and specific resistance will remain uncharged
- C. Resistance will be halved and specific resistance will be doubled
- D. Resistance and specific resistance will both remain uncharged
Explanation: Correct option is B. The formula for resistance of wire is given by: ρ = RA/l. In Specific resistance there will be no Change .
Correct answer: Resistance will be halved and specific resistance will remain uncharged- A. Minimum
- B. Constant
- C. Maximum
- D. Varying
Explanation: The potential difference, also known as voltage, is the driving force that pushes the charges to flow in the circuit.
Correct answer: Constant- A. 1 x 10^-7
- B. 2.63 x 10^-8
- C. 19 x 10^-8
- D. 7.85 x 10^-8
Explanation: The resistivity (ρ) of the wire can be calculated using the formula: ρ = (RA) / L where R is the resistance of the wire, A is its…
Correct answer: 1 x 10^-7- A. 2KWh
- B. 20KWh
- C. 6KWh
- D. 12KWh
Explanation: To calculate the electrical power consumption, we can use the formula:Power (in kilowatts) = (Wattage × Time) / 1000Given that the…
Correct answer: 2KWh- A. Reactance of generator
- B. Input torque
- C. Losses
- D. Reactants 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