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.
Last updated
1,052 questions · page 47 of 53
- A. A charge of 5 C flows through a point in 1 second
- B. 5V electricity is causing 1 C af charge to flow
- C. 5 V electricity flows across 1 Ω of resistance
- D. A charge of 5 C flows through a point in 5 seconds
Explanation: A is correct. Current= q/t. so 5A means 5C flowing in one sec from a point.
Correct answer: A charge of 5 C flows through a point in 1 second- A. 400oC
- B. 450oC
- C. 500oC
- D. 550oC
Explanation: C is the correct option temperature coefficient =Rt-Ro/Ro x t (Rt is 3 times Ro) 4×10-3=(12×10-3)-(4×10-3) /(4×10-3) x t t= 500°C
Correct answer: 500oC- A. They have equaI currents through them
- B. The resistance of the filaments in both the bulbs is same through them
- C. The resistance of the filament in 40 watt bulb is more than the resistance in 100 watt bulb
- D. The resistance of the filament in 100 watt bulb is more than the resistance in 40 watt bulb
Explanation: As bulbs are in parallel, they will have same volatge. So, P is inversely proportional to R. Hence, 40 watt bulb will have more resistance.
Correct answer: The resistance of the filament in 40 watt bulb is more than the resistance in 100 watt bulb- A. R1 = R2 = R3
- B. R1 > R2 > R3
- C. R3 > R2 > R1
- D. R2 > R3 > R1
Explanation: V=IR, current is inversely proportional to resistance. The line which is most closest to I axis has the least resistance and vice versa.
Correct answer: R3 > R2 > R1- A. Potential difference across R1 is higher
- B. Current through R1 is greater than in R2
- C. Power consumed in R1 is greater than in R2
- D. None of these
Explanation: In a parallel circuit, all resistors have the same potential difference across them, regardless of their resistance.
Correct answer: None of these- A. 2/6 Ampere
- B. 3/6 Ampere
- C. 4/6 Ampere
- D. 5/6 Ampere
Explanation: To find the current through the 30 Ω resistor, you need to determine the potential difference across it.
Correct answer: 5/6 Ampere- A. If only I follows
- B. If only II follows
- C. If either I or II follows
- D. If neither I nor II follows
- E. If both I and II follow
Explanation: Both suggested courses of action fail to tackle the actual problem of Mr. X's behavior, and therefore, neither is appropriate.
Correct answer: If neither I nor II follows- A. Vt=0
- B. Vt < E
- C. Vt = E
- D. Vt = E - Ir
Explanation: In an open circuit, the terminal voltage (Vt) is equal to the source voltage (E).
Correct answer: Vt = E- A. External resistance
- B. Internal resistance
- C. Both
- D. None
Explanation: The correct answer is internal resistance, which refers to the opposition to the flow of current caused by the materials and reactions…
Correct answer: Internal resistance- A. low.
- B. zero.
- C. high.
- D. constant.
Explanation: The terminal potential difference (V) of a battery is given by the formula \(V=E-Ir\), where E is the electromotive force (e.m.f.), I is…
Correct answer: zero.- A. The circuit is closed.
- B. The circuit is opened.
- C. Its circuit resistance is minimum.
- D. Its internal resistance is maximum.
Explanation: The electromotive force (emf) of a battery is defined as the potential difference across its terminals when no current is flowing through…
Correct answer: The circuit is opened.- A. E = 2 V and r = 0.4 Ω.
- B. E = 0.4 V and r = 2 Ω.
- C. E = 0.5 V and r = 0.4 Ω.
- D. E = 0 V and r = 2.5 Ω.
Explanation: The correct answer is Option B:E = 0.4 V and r = 2 Ω.. In a V-I graph, the y-intercept represents the electromotive force (E) of the cell…
Correct answer: E = 0.4 V and r = 2 Ω.- A. oo
- B. 0
- C. R
- D. R/2
Explanation: The maximum output power is delivered to a load resistance ( R ) when the internal resistance ( r ) of the source is equal to the load…
Correct answer: R- A. r = 0
- B. r = R
- C. r < R
- D. r > R
Explanation: The condition for maximum power transfer from a source of emf to an external circuit occurs when the load resistance ( R ) is equal to the…
Correct answer: r = R- A. I only.
- B. III only.
- C. I and II.
- D. I and III.
Explanation: To achieve maximum power dissipation in an external resistance connected to a dry cell with internal resistance, the effective internal…
Correct answer: I only.- A. 2R
- B. 4R
- C. 8R
- D. 16R
Explanation: The resistance (R) of a wire is given by formula: R = ρ L/Awhere ( ρ ) is the resistivity of the material, ( L ) is the length of the…
Correct answer: 16R- A. Double
- B. Half
- C. four time
- D. Eight time
Explanation: When a wire with uniform cross-sectional area ( A ) and length ( L ) is cut into two equal parts, the resistance of each part becomes ( R'…
Correct answer: Half- A. Conductivity
- B. Conductance
- C. Resistance
- D. Resistivity
Explanation: The slope of the current-voltage (I-V) graph for a resistor is numerically equal to the reciprocal of the resistance (conductivity) (1/R)…
Correct answer: Conductivity- A. R/4
- B. 4R
- C. 16R
- D. R/2
Explanation: The resistance of a wire is given by the formula: R=ρL /Awhere:R is the resistance,ρ is the resistivity of the material,L is the length of…
Correct answer: 16R- A. Ω-m2
- B. (Ω-m)-1
- C. Ω-m
- D. (Ω-m)-2
Explanation: Resistivity (ρ) is a fundamental property of materials that quantifies how strongly a material opposes the flow of electric current.
Correct answer: Ω-m