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. P=IV
- B. P=V/I
- C. p= V+I
- D. p=VQ
Explanation: he three formulas for calculating power are:- P = V x I, where P is power, V is voltage, and I is current.- P = I^2 x R, where P is power…
Correct answer: P=IV- A. °C
- B. °C-1
- C. m°C-1
- D. None of these
Explanation: The temperature coefficient of resistance (TCR) is a measure of how much the resistance of a material changes with temperature.
Correct answer: °C-1- A. No bulb will light
- B. All the four bulbs will light
- C. Rest of three bulbs will light
- D. Above B and C
Explanation: If one bulb fuses, the rest will continue to work. When bulbs are connected in parallel, each bulb is connected to the power supply…
Correct answer: Rest of three bulbs will light- A. 0.8A
- B. 8A
- C. 80A
- D. 18A
Explanation: R = I/V = 10/1 = 10Ω I = V/R = 8/10 = 0.8 A
Correct answer: 0.8A- A. More resistance
- B. No resistance
- C. Less resistance
- D. Same resistance
Explanation: R = p L/A Thick wires have less resistance than thin wires because of their greater cross-sectional area.
Correct answer: Less resistance- A. 0.016 per degree Celsius
- B. 32 per degree Celsius
- C. 0.018 per degree Celsius
- D. 0.00106 per degree Celsius
Explanation: According to the formula,R = Ro(1 +α ΔT)Or R = Ro + Roα ΔTOr R - Ro = Roα ΔTOr α = (R - Ro)/ RoΔTHere, R = resistance at given…
Correct answer: 0.016 per degree Celsius- A. Changing
- B. Absolute zero
- C. Constant
- D. None of these
Explanation: This is one of the conditions of Ohm's law that it is applicable only when the temperature of the conductor remains constant.
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: Given: Current = I = 0.75 APotential difference = V = 1.5 V Length = L = 5 mCross-sectional area =A= 2.5 × 10-7m² Resistivity = p =…
Correct answer: 1 x 10^-7- A. Increase in temperature
- B. Increase in cross-sectional area
- C. Decrease in length
- D. Decrease in cross-sectional area
Explanation: Option A is correct since by increasing the temperature, the specific resistance of a conductor increases, and a semiconductor…
Correct answer: Increase in temperature590. If a current of 5 Amperes flows through the conductor. The number of electrons per second will is
- A. 1.6 x 10^19
- B. 3.12 x 10^19
- C. 4 x 10^19
- D. 7.68 x 10^20
Explanation: To calculate the number of electrons per second in a conductor, we can use the equation: number of electrons = (current × time) / (charge…
Correct answer: 3.12 x 10^19- A. Temperature
- B. Nature of a conductor
- C. Length
- D. Color
Explanation: The resistance of a conductor is determined by the formula: R = ρ(L/A), where R is resistance, ρ is resistivity, L is length, and A is…
Correct answer: Length- A. 1.6 ohm
- B. 1.5 ohm
- C. 1.7 ohm
- D. 1.8 ohm
Explanation: R = V / ISubstituting the given values, we get:R = 45 V / 30 A = 1.5 ohmTherefore, the resistance of the circuit is 1.5 ohm
Correct answer: 1.5 ohm- A. 50W
- B. 75W
- C. 100W
- D. 90W
Explanation: The equation for power is given by,P = V IPutting values,P = 250 V × 0.3 AP = 75 W
Correct answer: 75W- A. Increasing the e.m.f. of the primary coil
- B. Increasing the Potential gradient
- C. increasing the length of the potentiometer wire
- D. Decreasing the length of the potentiometer wire
Explanation: The sensitivity of a potentiometer can be increased by increasing the length of the potentiometer wire.The sensitivity of a potentiometer…
Correct answer: increasing the length of the potentiometer wire- A. 2.2mA
- B. 2.2/v2 mA
- C. 2.2 x v2 mA
- D. None of the above
Explanation: We know that,V = IRI = VRI = 220V/100k.ohmI = 2.2 mA
Correct answer: 2.2mA- A. 330W
- B. 430W
- C. 530W
- D. 500W
Explanation: Power = current x voltage = 1.5 x 220 P=330 watt
Correct answer: 330W- A. Multimeter
- B. Ammeter
- C. Galvanometer
- D. Voltmeter
Explanation: Correct Option: A This option is correct because a multimeter is a test tool used to measure two or more electrical values principally…
Correct answer: Multimeter- A. Copper has high electrical resistivity
- B. Copper has low electrical resistivity
- C. Copper has low electrical conductivity
- D. Copper has high value of elasticity
Explanation: Correct Option: BThis option is correct because copper is a conductor so it offers less resistance to the flow of charges.
Correct answer: Copper has low electrical resistivity- A. Temperature
- B. Nature of conductor
- C. Length
- D. None of these
Explanation: Correct Option:CThe resistance of a conductor depends on various factors, but one of the primary factors is the length of the conductor.
Correct answer: Length600. 1 Watt = _.
- A. 1 VA
- B. 1 V/A
- C. 1 A/V
- D. 1/AV
Explanation: Watts (W) is the unit of measurement for power, which is the rate at which energy is transferred or transformed.
Correct answer: 1 VA