Free Steady Current MCQs with Answers
87 Steady Current 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 is the continuous flow of charge at a constant rate through a conductor. The topic covers current, charge, potential difference, resistance, Ohm's law, resistivity and electrical power, along with series and parallel circuits, while distinguishing conventional current direction from electron motion.
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- A. the charge flowing per unit time past a point in the circuit
- B. the energy delivered per unit charge
- C. the resistance per unit length
- D. the potential difference per unit resistance only
Explanation: One ampere is one coulomb per second, so current measures rate of flow of charge.
Correct answer: the charge flowing per unit time past a point in the circuit- A. inversely proportional to the potential difference across it
- B. directly proportional to the potential difference across it
- C. independent of the potential difference
- D. proportional to the square of the potential difference
Explanation: A graph of current against voltage for an ohmic conductor is a straight line through the origin whose gradient is the reciprocal of the…
Correct answer: directly proportional to the potential difference across it- A. each receives the full mains voltage and can be switched independently
- B. the total resistance is increased
- C. the current through each is the same
- D. less current is drawn overall
Explanation: In parallel every appliance sees the same 220 V and switching one off leaves the others unaffected, whereas a series chain would fail…
Correct answer: each receives the full mains voltage and can be switched independently- A. thick wire of low melting point placed in parallel with the appliance
- B. thin wire of low melting point placed in series with the appliance
- C. high resistance placed in parallel with the supply
- D. device that raises the current to a safe value
Explanation: Being in series, the whole current passes through it, and being thin with a low melting point it melts and breaks the circuit if that…
Correct answer: thin wire of low melting point placed in series with the appliance- A. energy
- B. charge
- C. momentum
- D. resistance
Explanation: The total current entering a junction equals the total leaving, because charge cannot accumulate at a point in a steady circuit.
Correct answer: charge- A. very high resistance
- B. very low resistance, so it hardly alters the current it measures
- C. infinite resistance
- D. the same resistance as the circuit
Explanation: Since the whole current flows through it, any appreciable resistance would reduce that current and falsify the reading, so an ideal…
Correct answer: very low resistance, so it hardly alters the current it measures7. In a metal, the drift velocity of the electrons that make up a current of a few amperes is typically
- A. close to the speed of light
- B. about 1000 m per second
- C. of the order of a millimetre per second
- D. exactly zero
Explanation: Electrons drift extremely slowly because there are so many of them, roughly 10 to the 28 per cubic metre, so a small average velocity…
Correct answer: of the order of a millimetre per second- A. be quadrupled
- B. be doubled
- C. be halved
- D. remain unchanged
Explanation: Drift velocity is proportional to the electric field, and for a wire of fixed length the electric field is proportional to the applied…
Correct answer: be doubled- A. Divider
- B. Shunt
- C. Multiplier
- D. None of these
Explanation: A shunt is a very low-resistance path connected in parallel to bypass part of the current around a component or measuring instrument.
Correct answer: Shunt- A. IR Drops
- B. Battery emf
- C. junction voltages
- D. both "1" and "2"
Explanation: Kirchhoff's second rule states that the algebraic sum of potential changes around a closed loop is zero, so the total battery emf equals…
Correct answer: both "1" and "2"- A. Metric system
- B. Metric or French system of units
- C. Metric or British system of units
- D. None of these
Explanation: The CGS system is based on centimetre, gram and second, and is a metric system historically called the French system.
Correct answer: Metric or French system of units- A. one electron
- B. 10 -6 electrons
- C. 106 electrons
- D. 6.25 x 10^12 electrons
Explanation: Current is charge transferred per second, so the number of electrons per second is I/e = 1 x 10^-6 coulomb per second ÷ 1.6 x 10^-19…
Correct answer: 6.25 x 10^12 electrons- A. Protons
- B. Electrons
- C. Metal atoms
- D. Metal ions
Explanation: In a solid metal, positive ions remain fixed in the crystal lattice while loosely bound electrons can drift through the conductor.
Correct answer: Electrons- A. Electric current
- B. Electric charge
- C. Plane angle
- D. Amount of substance
Explanation: Electric charge is derived from electric current and time: Q = It, so its SI unit is coulomb = ampere second.
Correct answer: Electric charge- A. 4 volt
- B. 5 volt
- C. 2 volt
- D. 0.4 volt
Explanation: Using Ohm's law, the potential difference is V = IR = (0.020 A)(100 Ω) = 2.0 V.
Correct answer: 2 volt- A. very low damping
- B. very high damping
- C. no damping at all
- D. radial field disintegration
Explanation: A galvanometer uses low damping so even a small current can produce a noticeable deflection, although the pointer may take longer to…
Correct answer: very low damping- A. in series with the circuit
- B. in parallel with circuit
- C. in series with any of the parallel resistances in the circuit
- D. in parallel with any of the series resistances in the circuit
Explanation: An ammeter must be placed in series so the same current flowing through the circuit passes through the meter.
Correct answer: in series with the circuit- A. 18Ω
- B. 30Ω
- C. 24Ω
- D. 12Ω
Explanation: The deflection falls from 50 divisions to 25 divisions, so the galvanometer current becomes half its original value.
Correct answer: 12Ω- A. detect current in a circuit
- B. measure current flowing through a circuit
- C. measure voltage across a circuit
- D. measure potential difference between two points in a circuit
Explanation: A galvanometer is a sensitive instrument used to detect the presence and direction of a small current by the deflection of its coil.
Correct answer: detect current in a circuit- A. 2.0 mA
- B. 20 mA
- C. 200 mA
- D. 0.2 mA
Explanation: Using I = V/R, the maximum safe current is I = 100 mV / 50 Ω = 0.100 V / 50 Ω = 0.002 A = 2.0 mA.
Correct answer: 2.0 mASteady Current MCQs: common questions
Are these Steady Current MCQs free?
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How many Steady Current MCQs are on this page?
There are 87 Steady Current MCQs in the Physics bank, shown 20 to a page with the correct answer and an explanation on each.
Does every Steady Current MCQ have an explanation?
Yes. Each Steady Current question shows the correct option and a written explanation of why it is correct, so a wrong answer teaches you something rather than just being marked wrong.
Can I take a timed Steady Current test?
Yes. The practice button on this page starts a free Steady Current test drawn from the Physics bank. It marks each answer instantly, gives you a score at the end, and can be retaken as many times as you like.