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. negative charges
- B. positive charges
- C. both negative and positive charges
- D. neutral particles
Explanation: In liquids and gasses, the current is due to the motion of both negative and positive charges.
Correct answer: both negative and positive charges- A. 64 W
- B. 72 W
- C. 100 W
- D. neutral particles
Explanation: The power consumed by the bulb can be calculated using the formula P=V2/R, where P is power, V is voltage and R is resistance.
Correct answer: 72 W- A. hyperbola
- B. ellipse
- C. parabola
- D. straight line
Explanation: The graphical representation of Ohm's law is a straight line. Ohm's law states that the current (I) flowing through a conductor is…
Correct answer: straight line- A. Electrons: downwards, conventional current: downwards
- B. Electrons: upwards, conventional current: downwards
- C. Electrons: downwards, conventional current: upwards
- D. Electrons: upwards, conventional current: upwards
Explanation: In a lightning flash, the lower part of the cloud becomes negatively charged.
Correct answer: Electrons: downwards, conventional current: upwards- A. 20V
- B. 0.8V
- C. 12V
- D. 1.25V
Explanation: By ohms law, Voltage between 1 and 2V(1,2)= (3+2)*4V(1,2)= 20 volts thus⇒Option A is correct
Correct answer: 20V- A. 0.1A
- B. 0.6A
- C. 2A
- D. 0.5A
Explanation: The high-resistance voltmeter, which is connected across the 9.0V battery, reads a p.d. of 7.5V.
Correct answer: 0.5A- A. high power
- B. high voltage
- C. high current
- D. over heating
Explanation: A fuse is placed in series with a circuit to protect against high current.
Correct answer: high current- A. zero
- B. 4 V
- C. 2.0 V
- D. 16 V
Explanation: The potential difference (V) is equal to the work done (W) per unit charge (Q), i.e., V=W/Q .
Correct answer: 2.0 V- A. depends on the system of units only
- B. depends on the medium between the charges only
- C. depends on both the system of units and the medium between the charges
- D. is independent of both the system of units and the medium between the charges
Explanation: The constant k in Coulomb's law is known as the Coulomb's constant and has a value of 8.9875×10^9N m^2/C^2.
Correct answer: is independent of both the system of units and the medium between the charges- A. VI
- B. I^2R
- C. V^2/R
- D. all of these
Explanation: The electrical power P is given by P=VI, where V is the voltage and I is the current.
Correct answer: all of these- A. 4
- B. 3
- C. 2
- D. 1
Explanation: A rheostat typically has two terminals. It is a variable resistor used to control the current in a circuit by varying the…
Correct answer: 2- A. CRO
- B. AVO meter
- C. both CRO & AVO meter
- D. potentiometer
Explanation: A potentiometer is an instrument used to measure the electromotive force (emf) and internal resistance of a cell accurately.Incorrect…
Correct answer: potentiometer- A. temperature
- B. nature of the material
- C. both temperature and nature of the material
- D. temperature, length & nature of the material
Explanation: Resistivity (ρ) of a conductor depends on both the temperature and the nature of the material.
Correct answer: both temperature and nature of the material- A. low potential to high potential
- B. high potential to low potential
- C. high temperature to low temperature
- D. low temperature to high temperature
Explanation: Conventional current flow assumes positive charges moving from a higher potential (voltage) to a lower potential.
Correct answer: low potential to high potential- A. varies with its length
- B. varies with its mass
- C. varies with its cross section
- D. does not depend on its length, cross section, and mass
Explanation: The specific resistance of a wire, also known as resistivity, is an intrinsic property of the material and does not depend on the length…
Correct answer: does not depend on its length, cross section, and mass- A. 2 Ω
- B. 6 Ω
- C. 8/3Ω
- D. 12 Ω
Explanation: When three equal resistances are connected to form a triangle, the equivalent resistance between any two terminals is twice the resistance…
Correct answer: 8/3Ω- A. charge only
- B. both energy and momentum
- C. energy only
- D. both charge and energy
Explanation: Kirchhoff's laws, namely Kirchhoff's voltage law (KVL) and Kirchhoff's current law (KCL), are manifestations of the conservation of both…
Correct answer: both charge and energy- A. 10r
- B. r/100
- C. r/10
- D. r/5
Explanation: To obtain the minimum resistance, the resistors should be connected in parallel.
Correct answer: r/10- A. black, black, brown, silver
- B. brown, black, black, gold
- C. black, brown, black, gold
- D. brown, brown, black, gold
Explanation: The colour code 102 corresponds to the resistance value of 1, 0, and 2 (brown, black, black).
Correct answer: black, brown, black, gold- A. On Anode
- B. On Cathode
- C. Either anode or cathode
- D. Can not be deposited
Explanation: During electrolysis, positive ions migrate towards the cathode (negative electrode) and get reduced.
Correct answer: On Cathode