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 42 of 53
- A. 4R
- B. 3R
- C. 2R
- D. R
Explanation: When length is halved, resistance is halved.When diameter is halved, area is divided by 4 (square relationship) hence, resistance is…
Correct answer: 2R- A. Law of conservation of momentum
- B. Law of conservation of mass
- C. Law of conservation of energy
- D. Law of conservation of charge
Explanation: Kirchhoff's current law (1st Law) states that current flowing into a node (or a junction) must be equal to current flowing out of it.
Correct answer: Law of conservation of charge- A. Emf of the cell
- B. P.D in the circuit
- C. Current in the cell
- D. Current in the circuit
Explanation: The emf of the battery in the potentiometer experiment should be greater than the emf of the cell to be determined because The fall of…
Correct answer: Emf of the cell- A. Decrease in temperature and decrease in resistance
- B. Increase in temperature and increase in resistance
- C. Decrease in temperature and increase in resistance
- D. Increase in temperature and decrease in resistance
Explanation: At a higher value of current, sufficient heat is produced which raises the temperature of the resistor and causes an increase in resistance.
Correct answer: Increase in temperature and increase in resistance- A. 0.1 K-1
- B. 0.02 K-1
- C. 0.01 K-1
- D. 0.2 K-1
Explanation: You can solve the question using following solution:
Correct answer: 0.1 K-1- A. 30
- B. 35 A
- C. 40 A
- D. 45 A
- E. 93 A
Explanation: V=9 volts R=0.2 ohm I= ? V=IR => I = V/R I = 9 volts / 0.2 ohm I = 45 Ampere So , option D is correct.As this question is theoretical…
Correct answer: 45 A- A. 6/R
- B. 3/R
- C. R/9
- D. R/3
Explanation: 3/R: This option suggests that the equivalent resistance of the parallel combination of the three equal parts is 3/R.
Correct answer: R/9- A. Non-linear
- B. Curve
- C. Linear
- D. Curvilinear
Explanation: The resistance increases as the temperature of the metallic conductor increases.
Correct answer: Linear- A. 1.6 Ohms
- B. 1.5 Ohms
- C. 1.7 Ohms
- D. 1.8 Ohms
Explanation: We know that V = IRRearranging this formula gives:R= V/I= 45/30= 3/12= 1.5 OhmsAs it is numerical so it can have only one possible answer.
Correct answer: 1.5 Ohms- A. Electromechanical device
- B. Electrosolar device
- C. Electrothermal device
- D. None of these options is correct
Explanation: Option A) A galvanometer is an electromechanical measuring instrument for electric current.Option B) Electrosolar device is incorrect…
Correct answer: Electromechanical device- A. Increases or decreases as the temperature rises, depending upon the metal
- B. Decreases as the temperature rises
- C. Independent of temperature
- D. Increases as the temperature rises
Explanation: V/T = R and for metals R ↑, on ↑ in the temperature.
Correct answer: Increases as the temperature rises- A. 4 x 10^-28 m-3
- B. 1.6 x 10^-27 m-3
- C. 2.5 x 10^-27 m-3
- D. 6.3 x 10^28 m-3
- E. 1.3 x 10^34 m-3
Explanation: The formula for electric current relating the drift velocity is: I = neAV Where;I = Electric current n = Number of charges per unit volume…
Correct answer: 6.3 x 10^28 m-3- A. 1 A
- B. 2 A
- C. 4 A
- D. 6 A
- E. Infinite
Explanation: Current in the circuit is I = E/r + R = 4/r + 2 = 1or 2 + r = 4or r = 2 ohmsWhen the terminals of battery are connected directly, the…
Correct answer: 2 A- A. 8 x 10^4 Joules
- B. 12 x 10^5 Joules
- C. 19 x 10^5 Joules
- D. 23 x 10^5 Joules
- E. 37 x 10^5 Joules
Explanation: Energy=Power x timeEnergy=2000 x 10 x 60Energy=12 x 105 J
Correct answer: 12 x 10^5 Joules- A. 2 Ω
- B. 3 Ω
- C. 1 Ω
- D. 6 Ω
Explanation: The maximum power transfer theorem states that maximum power is transferred when the load resistance is equal to the source resistance.
Correct answer: 3 Ω- A. 5 Ω
- B. 20 Ω
- C. 50 Ω
- D. Cannot be determined
Explanation: To solve this problem, we use Ohm's Law and the concept of equivalent resistance.
Correct answer: 5 Ω- A. 3 V
- B. 1 V
- C. 4 V
- D. 5 V
Explanation: To find the potential at point O, we apply Kirchhoff's Current Law (KCL), which states that the sum of currents entering a junction equals…
Correct answer: 3 V- A. 8 V
- B. 16 V
- C. 24 V
- D. 32 V
Explanation: To solve this problem, we use Ohm's Law, V = IR. Given that the potential drop across the 6 Ω resistor is 12 V, we can calculate the…
Correct answer: 24 V- A. 2ε/r
- B. 2ε/3r
- C. ε/3r
- D. ε/r
Explanation: In this arrangement, you have 3n cells, each with emf ε and internal resistance r, connected in series.
Correct answer: ε/3r- A. 1 A
- B. 2 A
- C. Zero
- D. 0.5 A
Explanation: Option C is correct because the given circuit is a balanced Wheatstone bridge. So, the current through the 5Ω resistor is zero.
Correct answer: Zero