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 40 of 53
- A. Increases with increase in its internal resistance
- B. Decrease with increase in internal resistance
- C. Is independent of its internal resistance
- D. None of these
Explanation: As; E= IR+IrIf internal resistance increases, Ir increases and IR=V= terminal potential difference decreases because E=emf of the battery…
Correct answer: Decrease with increase in internal resistance- A. The same
- B. Different
- C. Both of them
- D. None of them
Explanation: Option A is correct since in a parallel circuit, the voltage across each of the components is the same, and the total current is the sum…
Correct answer: The same- A. P=V/I
- B. P=VI
- C. 2P=l+V
- D. All of them
Explanation: Option B is correct since the formula to calculate power is 'voltage x current'.
Correct answer: P=VI- A. temperature
- B. nature of a conductor
- C. length
- D. None of these
Explanation: Option C is correct since the resistance of a wire is directly proportional to its length and inversely proportional to its…
Correct answer: length- A. Increasing the e.m.f. of the primary cell
- B. Increasing the potential gradient
- C. Increasing the length of the potentiometer wire
- D. Decreasing the length of the potentiometer wire
Explanation: A potentiometer's accuracy (sensitivity) is inversely dependent upon the potential gradient.
Correct answer: Increasing the length of the potentiometer wire- A. 5 kJ
- B. 10 kJ
- C. 15 kJ
- D. 20 kJ
Explanation: By applying the formula P = I2R = 52x2 = 50WThen, E = PxT = 50x300 = 15,000 WS = 15 kJ.
Correct answer: 15 kJ- A. Zero resistance
- B. Load resistance
- C. Max resistance
- D. None of these options are correct
Explanation: The maximum power is delivered to a load when the load resistance is equal to the internal resistance of the source.
Correct answer: Load resistance- A. 150V
- B. 250V
- C. 50V
- D. 15V
Explanation: Ohm's Law : V = IR. So, V = (5)(50) = 250 V. Hence Option B is correct.
Correct answer: 250V789. Electric power is _.
- A. Ratio of electric work done per unit time
- B. Voltage per unt time
- C. Electric charge per unit time
- D. Current per unit time
Explanation: Power is simply defined as the rate of doing work or work done / time. Therefore electric power can be defined as the rate of electric…
Correct answer: Ratio of electric work done per unit time- A. 0.9 Amp
- B. 0.6 Amp
- C. 2 Amp
- D. 3 Amp
Explanation: Power = IV therefore I = P/V = 200/220 = 0.9 A. Hence Option A is correct.
Correct answer: 0.9 Amp- 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. Conductivity
- B. Resistivity
- C. Resistance
- D. Inductance
Explanation: The reciprocal of the conductance is resistance.
Correct answer: Resistance- A. 5 volts
- B. 3 volts
- C. 15 volts
- D. 9 volts
Explanation: Here is the terminal potential:V = E - IR =12-(60×5×10−2) =12-3 =9V
Correct answer: 9 volts- A. Resistance increases with an increase in temperature
- B. Resistance decreases with an increase in temperature
- C. Resistance decreases with decrease in temperature
- D. Resistance is independent of temperature change
Explanation: A negative coefficient for a material means that its resistance decreases with an increase in temperature.
Correct answer: Resistance decreases with an increase in temperature- A. 1 kWh
- B. 1.5 kWh
- C. 2 kWh
- D. 3 kWh
Explanation: Work done is equal to energy which is power divided by timeE=P x tP =I2 x R = 52 x 20 = 500 WE = 500 x 3 = 1500 J1500 J = 1.5kWh
Correct answer: 1.5 kWh- A. Comparing two voltages
- B. Measuring current
- C. Comparing two currents
- D. Measuring voltage
Explanation: A potentiometer is an instrument for measuring voltage or 'potential difference' by comparison of an unknown voltage with a known…
Correct answer: Comparing two voltages- A. The potential must increase
- B. The potential must decrease
- C. The electric field strength must increase
- D. The electric field strength must decrease
Explanation: E is directed from higher to lower levels of V (from higher potential to lower potential).
Correct answer: The potential must decrease- A. 105 Q
- B. 0.01 Q
- C. 2.5 Q
- D. 3.9 Q
- E. 4.7 Q
Explanation: To convert the galvanometer into an ammeter of range 10.0 A, a shunt resistance (Rs) must be connected in parallel with the galvanometer.
Correct answer: 0.01 Q- A. 0.36 A
- B. 2.36 A
- C. 3.39 A
- D. 4.49 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 C-1
- B. 3.69 x 10^-3 C-1
- C. 6.31 x 10^-3 C-1
- D. 4.66.x 10-3 C-1
- E. 9.49 x 10^-3 C-1
Explanation: Ro=10Ω- Rt=20Ω- t=273∘C- Ro=Rt (1+αt)- α=Rt−Ro/Rot- α=20−10/10 × 273- α= 1/273- α= 3.66 x 10-3 C-l
Correct answer: 3.66 x 10^-3 C-1