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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1,052 questions · page 36 of 53
- A. V2R
- B. V2Rt
- C. I2R
- D. I2Rt
- E. IR
Explanation: power (P) dissipated in a resistor can be determined using the formula: Power = Voltage * Current.
Correct answer: I2Rt- A. 30.5 ampere
- B. 20 ampere
- C. 4 ampere
- D. 10 ampere
- E. 2 ampere
Explanation: When resistors are connected in parallel, the potential difference across each resistor is the same.
Correct answer: 2 ampere- A. Both the current and voltage must be low
- B. The current must be low and voltage high
- C. Both the current and voltage must be high
- D. The voltage must be zero and current low
- E. The voltage must low and current high
Explanation: For efficient transfer of electricity through cables over long distances, the preferable approach is to have: option b) The current must…
Correct answer: The current must be low and voltage high- A. The same
- B. One fourth
- C. √2 times
- D. Halved
- E. Doubled
Explanation: When a conducting wire is cut into two equal parts, the resistivity (ρ) of each part remains the same.
Correct answer: The same705. Four cells of emf 3volt are connected in series to form a battery. Net emf of the combination is:
- A. 12volt
- B. 1.33volt
- C. 9volt
- D. 7volt
- E. 3volt
Explanation: When cells are connected in series, the net electromotive force (EMF) of the combination is equal to the sum of the individual EMFs.
Correct answer: 12volt- A. 0 V
- B. 1V
- C. 2V
- D. 3V
Explanation: When a switch is closed, it becomes a conducting path, allowing the flow of electric current.
Correct answer: 0 V- A. area
- B. resistivity
- C. length
- D. mass
Explanation: The resistance of a conductor does not directly depends on mass. Resistance is determined by factors like resistivity, length, and area…
Correct answer: mass- A. Kirchhoff's current rule based upon the law of conservation of charge
- B. Wheatstone bridge is an application of Kirchhoffs rule
- C. Kirchhoff's rules are more suitable in AC circuits
- D. Klrchhoff's voltage rule based upon the law of conservation of energy
Explanation: Kirchhoff's rules, specifically Kirchhoff's current rule, and Kirchhoff's voltage rule, are fundamental principles in analyzing and…
Correct answer: Kirchhoff's rules are more suitable in AC circuits- A. high temperature coefficient
- B. negative temperature coefficient
- C. positive temperature coefficient
- D. zero temperature coefficient
Explanation: The substances whose resistance decreases with increase in temperature have negative temerpature coefficient resistance.
Correct answer: negative temperature coefficient- A. Current is divided
- B. EMF source is divided
- C. Resistance is divided
- D. Number of electrons are divided
Explanation: A potential divider is a simple circuit that uses resistors to supply a variable 'potential difference' (i.e., voltage).
Correct answer: Resistance is divided- A. 3R
- B. 9R
- C. 18R
- D. 27R
Explanation: Resistance is given by:⇒ R = ρ L / ASince, A = π r^2If its length is doubled its original value and its radius is reduced to one-third of…
Correct answer: 18R- A. 1:2
- B. 1:4
- C. 1:8
- D. 1:16
Explanation: Given data: Power of bulb A = P1 = 500W Power of bulb B = P2 = 2000W Voltage = V = 240V To find: The ratio of current passing through bulb…
Correct answer: 1:4713. A conductor has a length equal to pi meters and radius of r meters. Its resistance will be equal to:
- A. R = ρ/r1
- B. R = ρ/r2
- C. R = ρ/r3
- D. R = ρ/r4
Explanation: We know that resistance is given by:⇒ R = ρ L / A .........(i)Since, A = π r2 and according to given data, L = πSubstituting the values in…
Correct answer: R = ρ/r2- A. R
- B. 2R
- C. 3R
- D. 4R
Explanation: When two conductors each of resistance R are attached in series to an external circuit, their net resistance is equivalent resistance, R =…
Correct answer: 2R- A. Protons
- B. Ions
- C. Holes
- D. Electrons
Explanation: When metal is connected to a battery, the free electrons get accelerated due to the electric field (set up by the battery) and they gain…
Correct answer: Electrons- A. volt
- B. Coloumb
- C. watt
- D. eV
Explanation: The "volt" is the SI unit of potential difference, also known as voltage.
Correct answer: volt- A. work per unit charge
- B. force per unit charge
- C. power per unit charge
- D. force
Explanation: Electric potential is a measure of the electric potential energy per unit charge at a point in an electric field.
Correct answer: work per unit charge- A. resistance
- B. resistivity
- C. conductance
- D. conductivity
Explanation: Resistivity is a property of a material and is measured in ohm-meters (Ω·m).
Correct answer: resistivity719. 1eV is equal to
- A. 1.602 x 10^-19 J
- B. 16.20 x 10^-19 J
- C. 1620 J
- D. 162.0 x10^-19 J
Explanation: The conversion factor between electronvolts (eV) and joules (J) is given as:1 eV = 1.602 x 10^-19 JThis means that one electronvolt is…
Correct answer: 1.602 x 10^-19 J- A. length
- B. area
- C. temperature
- D. time
Explanation: he resistance of a wire is inversely proportional to its cross-sectional area.
Correct answer: area