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 33 of 53
- A. 4Ω
- B. 1 Ω
- C. 1/4 Ω
- D. 1/16 Ω
Explanation: When a wire of resistance 4R is bent in the form of circle, then the resistance of each segment across the diameter becomes 2R.Equivalent…
Correct answer: 1 Ω- A. The electric field strength must increase
- B. The electric field strength must decrease
- C. The potential must decrease
- D. None of these
Explanation: The correct answer is that the potential must decrease (Option C). Electric field lines are oriented from higher to lower electric…
Correct answer: The potential must decrease- A. Ωs
- B. Ωs-1
- C. Ω-1s
- D. Ω-1 s-1
Explanation: Farad is defined as charges held per unit of volt across the capacitor. Charges are current x time.
Correct answer: Ω-1s- A. 0.36A
- B. 2.36A
- C. 3.39A
- D. 4.49A
- E. 9.71A
Explanation: When the resistance is connected the potential difference drops from 2.2V to 1.8V.
Correct answer: 0.36A- A. 105 Ω
- B. 0.01 Ω
- C. 2.5 Ω
- D. 3.9 Ω
- E. 4.7 Ω
Explanation: Following formula is use to calculate shunt resistance:=(2 x 10-3 x 50)/(10 - 2 x 10-3)=0.1 / 9.998=0.01 ohmSo the correct option is B.
Correct answer: 0.01 Ω- A. 0.36 A
- B. 2.36 A
- C. 3.39 A
- D. 4.49 A
- E. 2.71 A
Explanation: In open circuit, E = V = 2.2 V, In close circuit, V = 1.8 V, R=5ΩSo internal resistance, r=(E/V−1) R =(2.2/1.8−1) × 5 ⇒ r=10/9= 1.1ΩNow V=…
Correct answer: 0.36 A- A. 3.66 x 10^-3 K-1
- B. 4.66 x 10^-3 K-1
- C. 6.31 x 10^-3 K-1
- D. 7.42 x 10^-3 K-1
- E. 9.49 x 10^-3 K-1
Explanation: To find the temperature coefficient of resistance (α) for platinum, use the formula Rt = Ro(1 + αt), where:Rt = resistance at temperature…
Correct answer: 3.66 x 10^-3 K-1- A. 105 Ω
- B. 0.01 Ω
- C. 2.5 Ω
- D. 3.9 Ω
- E. 4.7 Ω
Explanation: To convert a galvanometer to an ammeter with a specific range, a shunt resistor (Rs) is placed in parallel with the galvanometer.
Correct answer: 0.01 Ω- A. 1.0 eV
- B. 3.0 eV
- C. 5.0 eV
- D. 7.0 eV
Explanation: Photon velocity equals the speed of light. Photons are massless, but they have energy E = hf = hc/λ.
Correct answer: 1.0 eV- A. 7.4 N, + x direction
- B. 0.6 N, + x direction
- C. 0.6 N, - x direction
- D. 7.4 N, - x direction
Explanation: To determine the resultant force on the center charge, we need to consider the vector sum of the forces acting on it.
Correct answer: 0.6 N, + x direction- A. 2.4 N/C from A to B
- B. 2.4 N/C from B to A
- C. 6000 N/C from A to B
- D. 6000 N/C from B to A
Explanation: To calculate the electric field between the plates A and B, we can use the formula:Electric field (E) = Voltage (V) / Distance between…
Correct answer: 6000 N/C from A to B- A. 360 ± 5% Ω
- B. 970 ± 5% Ω
- C. 1500±5 Ω
- D. 2800 ± 5% Ω
Explanation: The color bands on a resistor are interpreted as follows: The first band (Brown) represents the first significant digit, which is 1.
Correct answer: 1500±5 Ω- A. I2 is smaller than I3 and I1
- B. I3 is greater than I2 and I1
- C. I2 is smaller than I1 but bigger than I3
- D. I2 is smaller than I3 but bigger than I1
Explanation: In the given circuit, I1 splits into I2 and I3. According to the principle of current division, both I2 and I3 must be smaller than I1.
Correct answer: I2 is smaller than I1 but bigger than I3- A. 0
- B. 1/2
- C. 2
- D. 3/2
Explanation: When a wire is molded in the form of a ring and carries a charge q, the electric field created by the ring at any point on its axis is…
Correct answer: 0- A. increase
- B. decrease
- C. become zero
- D. remain unchanged
Explanation: Electrostatic potential energy is the energy associated with the interaction between charged particles due to their electric fields.
Correct answer: increase- A. When 1 amp current is passed through 3 ohm resistor for 2 sec.
- B. When 1 amp current is passed through 2 ohm resistor for 3 sec.
- C. When 2 amps current is passed through 1 ohm resistor for 2 sec.
- D. When 3 amps current is passed through 1 ohm resistor for 1 sec.
Explanation: To determine the largest heating effect in joules, we use the formula H = I^2 * R * t for each scenario:Option A: H = (1^2) * 3 * 2 = 6…
Correct answer: When 3 amps current is passed through 1 ohm resistor for 1 sec.- A. Half of the first wire
- B. Same as the first wire
- C. Twice of the first wire
- D. Four times of the first wire
Explanation: If the length of the wire is four times and the diameter is twice, then the length becomes 4L and the diameter becomes 2d.
Correct answer: Same as the first wire658. If an electric iron of 120 ohms operates at 220 V, then the rate of heat developed is equal to:
- A. 0.54 W
- B. 1.83 W
- C. 65.45 W
- D. 403.33 W
Explanation: To determine the rate of heat developed by an electric iron, we can use the formula:Power (P) = (Voltage)^2 / ResistanceGiven that the…
Correct answer: 403.33 W- A. X _ Y _ Z
- B. Y _ X _ Z
- C. X _ Z _ Y
- D. Y_ Z _ X
Explanation: In a circuit diagram, the direction of the conventional current is typically represented as flowing from the positive terminal of a…
Correct answer: X _ Z _ Y- A. 600 J
- B. 600 Wh
- C. Depends on for how much time it is used
- D. 3.6 x 10^4 J
Explanation: The energy stored in a battery can be calculated using the formula: Energy (Wh) = Voltage (V) × Capacity (Ah).
Correct answer: 600 Wh