Current Electricity PYQ Practice

Class 12 Physics | JEE Main, JEE Advanced, NEET

Q1. A wire of resistance R is stretched to double its length. If volume remains constant, its new resistance is:

JEE Main • 2024

A) R

B) 2R

C) 4R

D) R/2

Answer: C

Q2. A 12 V battery of internal resistance 1Ω is connected to a 5Ω resistor. The current in the circuit is:

JEE Main • 2024

A) 1 A

B) 2 A

C) 3 A

D) 4 A

Answer: B

Q3. A current of 3 A flows through a conductor for 10 minutes. The charge passed through it is:

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A) 300 C

B) 600 C

C) 900 C

D) 1800 C

Answer: D

Q4. Two resistors 4Ω and 12Ω are connected in parallel. Their equivalent resistance is:

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A) 2Ω

B) 3Ω

C) 4Ω

D) 16Ω

Answer: B

Q5. A 10Ω resistor is connected across a 20 V battery. Power dissipated is:

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A) 20 W

B) 30 W

C) 40 W

D) 50 W

Answer: C

Q6. The drift velocity of electrons in a conductor is proportional to:

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A) current

B) area

C) resistance

D) length

Answer: A

Q7. The SI unit of electrical conductivity is:

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A) Ω m

B) Ω⁻¹ m⁻¹

C) Ω m⁻¹

D) Ω⁻¹ m

Answer: B

Q8. Kirchhoff’s junction law is based on conservation of:

JEE Main • 2021

A) energy

B) charge

C) momentum

D) mass

Answer: B

Q9. In a potentiometer experiment, at balance point the current drawn from the test cell is:

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A) maximum

B) minimum but non-zero

C) zero

D) infinite

Answer: C

Q10. A wire of resistance 5Ω is stretched to three times its length. Its resistance becomes:

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A) 15Ω

B) 25Ω

C) 45Ω

D) 60Ω

Answer: C

Q11. A cell of emf E and internal resistance r delivers maximum power to external resistance R when:

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A) R = 0

B) R = r

C) R = 2r

D) R = ∞

Answer: B

Q12. A 100 W, 200 V bulb has resistance:

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A) 100Ω

B) 200Ω

C) 300Ω

D) 400Ω

Answer: D

Q13. The slope of V-I graph of an ohmic conductor gives:

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A) conductance

B) resistance

C) power

D) charge

Answer: B

Q14. A current of 2 A flows through 5Ω resistor for 4 s. Heat produced is:

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A) 20 J

B) 40 J

C) 60 J

D) 80 J

Answer: D

Q15. In a balanced Wheatstone bridge, current through the galvanometer is:

JEE Advanced • 2017

A) zero

B) maximum

C) infinite

D) same as main current

Answer: A

Q16. A uniform wire has resistance R. It is cut into four equal parts and connected in parallel. Equivalent resistance is:

JEE Advanced • 2016

A) R/4

B) R/8

C) R/12

D) R/16

Answer: D

Q17. Two cells of emf E each and internal resistance r each are connected in parallel. Effective emf and internal resistance are:

JEE Advanced • 2015

A) E, r

B) 2E, r

C) E, r/2

D) 2E, r/2

Answer: C

Q18. If current density is J and electric field is E, conductivity is:

JEE Advanced • 2014

A) J/E

B) E/J

C) JE

D) 1/JE

Answer: A

Q19. The reciprocal of resistivity is called:

AIEEE • 2012

A) resistance

B) conductance

C) conductivity

D) current density

Answer: C

Q20. An ideal ammeter has resistance:

AIEEE • 2011

A) zero

B) low but finite

C) very high

D) infinite

Answer: A

Q21. An ideal voltmeter has resistance:

AIEEE • 2010

A) zero

B) low

C) very small

D) infinite

Answer: D

Q22. If potential difference across a resistor is doubled, power becomes:

AIEEE • 2009

A) 2 times

B) 4 times

C) half

D) same

Answer: B

Q23. The resistance of a conductor depends on:

AIEEE • 2008

A) length

B) area

C) material

D) all of these

Answer: D

Q24. The commercial unit of electrical energy is:

AIEEE • 2007

A) joule

B) watt

C) kilowatt-hour

D) ampere-hour

Answer: C

Q25. A 60 W bulb operates for 5 hours. Energy consumed is:

NEET • 2024

A) 0.03 kWh

B) 0.3 kWh

C) 3 kWh

D) 30 kWh

Answer: B

Q26. In metallic conductors, current is due to motion of:

NEET • 2023

A) protons

B) neutrons

C) free electrons

D) positive ions

Answer: C

Q27. A 4Ω and an 8Ω resistor are connected in series across 24 V. Current is:

NEET • 2022

A) 1 A

B) 2 A

C) 3 A

D) 4 A

Answer: B

Q28. If current through a conductor is 5 A, charge flowing in 2 s is:

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A) 2.5 C

B) 5 C

C) 10 C

D) 20 C

Answer: C

Q29. The unit of current density is:

NEET • 2020

A) A m

B) A m⁻¹

C) A m⁻²

D) A² m⁻²

Answer: C

Q30. The temperature coefficient of resistance of a semiconductor is generally:

NEET • 2019

A) positive

B) negative

C) zero

D) infinite

Answer: B

Q31. A fuse wire should have:

NEET • 2018

A) high melting point

B) low melting point

C) zero resistance

D) high density

Answer: B

Q32. The heating effect of current is given by:

NEET • 2017

A) Ohm’s law

B) Joule’s law

C) Faraday’s law

D) Lenz’s law

Answer: B

Q33. A 50 V source supplies 2 A current. Power supplied is:

NEET • 2016

A) 25 W

B) 50 W

C) 100 W

D) 200 W

Answer: C

Q34. A resistor converts electrical energy mainly into:

NEET • 2015

A) magnetic energy

B) heat energy

C) sound energy

D) nuclear energy

Answer: B

Q35. One volt is equal to:

AIPMT • 2014

A) 1 J/C

B) 1 C/J

C) 1 A/s

D) 1 W/A²

Answer: A

Q36. Ohmic conductors obey:

AIPMT • 2013

A) Boyle’s law

B) Ohm’s law

C) Joule’s law

D) Coulomb’s law

Answer: B

Q37. Potential gradient in a potentiometer means:

AIPMT • 2012

A) current per length

B) voltage per unit length

C) resistance per unit length

D) power per length

Answer: B

Q38. The dimensional formula of resistance is:

AIPMT • 2011

A) ML²T⁻³A⁻²

B) MLT⁻²

C) ML²T⁻²

D) MT⁻²A⁻¹

Answer: A

Q39. Equivalent resistance of two equal resistors R in parallel is:

AIPMT • 2010

A) 2R

B) R

C) R/2

D) R/4

Answer: C

Q40. In parallel combination, equivalent resistance is always:

AIPMT • 2009

A) greater than largest

B) less than smallest

C) equal to largest

D) infinite

Answer: B

Q41. A conductor of length L and area A has resistance R. If area is doubled keeping length same, resistance becomes:

JEE Main • 2026

A) R/2

B) R

C) 2R

D) 4R

Answer: A

Q42. A 3Ω, 6Ω and 2Ω resistor are connected in series. Equivalent resistance is:

JEE Main • 2025

A) 6Ω

B) 9Ω

C) 11Ω

D) 12Ω

Answer: C

Q43. Three resistors 2Ω, 3Ω and 6Ω are connected in parallel. Equivalent resistance is:

JEE Main • 2024

A) 1Ω

B) 2Ω

C) 3Ω

D) 6Ω

Answer: A

Q44. A circuit draws 0.5 A from a 220 V source. Power consumed is:

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A) 55 W

B) 110 W

C) 220 W

D) 440 W

Answer: B

Q45. If a conductor has conductance 0.2 S, its resistance is:

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A) 0.2Ω

B) 2Ω

C) 5Ω

D) 10Ω

Answer: C

Q46. The internal resistance of an ideal cell is:

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A) zero

B) 1Ω

C) very high

D) infinite

Answer: A

Q47. A 100Ω resistor is connected to 10 V battery. Current is:

NEET • 2026

A) 0.01 A

B) 0.1 A

C) 1 A

D) 10 A

Answer: B

Q48. Two 10Ω resistors in parallel have equivalent resistance:

NEET • 2025

A) 2Ω

B) 5Ω

C) 10Ω

D) 20Ω

Answer: B

Q49. If current is doubled through a resistor, heat produced in same time becomes:

NEET • 2024

A) 2 times

B) 4 times

C) half

D) same

Answer: B

Q50. A wire carries 120 C charge in 1 minute. Current is:

NEET • 2023

A) 1 A

B) 2 A

C) 3 A

D) 4 A

Answer: B

Current Electricity Assignment

Class 12 Physics | MCQs with View Solution

1. A wire of resistance 6Ω is stretched to double its length. Its new resistance becomes:

A) 6Ω
B) 12Ω
C) 18Ω
D) 24Ω

View Solution

Using R ∝ L² (volume constant)
New resistance = 6 × (2²) = 24Ω
Correct Answer: D

2. The drift velocity of electrons in a conductor depends on:

A) Current only
B) Potential difference only
C) Electric field only
D) Current and cross-sectional area

View Solution

Drift velocity v = I/(nAe). Hence depends on current and area.
Correct Answer: D

3. Two cells of emf 2V and internal resistance 1Ω each are connected in series with a 2Ω resistor. Current is:

A) 0.5A
B) 1A
C) 2A
D) 4A

View Solution

Total emf = 4V, total resistance = 2+1+1 = 4Ω
I = 4/4 = 1A
Correct Answer: B

4. A potentiometer measures emf more accurately because:

A) It has high resistance
B) It draws no current from source
C) It uses galvanometer
D) It has uniform wire

View Solution

At balance point no current is drawn from cell.
Correct Answer: B

5. Kirchhoff’s junction law is based on conservation of:

A) Energy
B) Momentum
C) Charge
D) Mass

View Solution

Sum of current entering equals leaving due to conservation of charge.
Correct Answer: C

6. A copper wire and an aluminium wire of same length and area are connected in series. Ratio of heat produced is:

A) 1:1
B) 2:1
C) ρCu : ρAl
D) ρAl : ρCu

View Solution

H = I²Rt, current same. Heat proportional to resistance and hence resistivity.
Correct Answer: C

7. The temperature coefficient of resistance of semiconductors is:

A) Positive
B) Negative
C) Zero
D) Infinite

View Solution

Resistance decreases with temperature in semiconductors.
Correct Answer: B

8. If the length of a potentiometer wire is increased, its sensitivity:

A) Increases
B) Decreases
C) Remains same
D) Becomes zero

View Solution

Potential gradient decreases, hence sensitivity increases.
Correct Answer: A

9. Current density has dimensions:

A) AL⁻²
B) AL²
C) A²L⁻²
D) AL⁻¹

View Solution

Current density = Current/Area.
Correct Answer: A

10. A 10Ω resistor dissipates 40W power. Current through it is:

A) 1A
B) 2A
C) 3A
D) 4A

View Solution

P = I²R ⇒ 40 = I²×10 ⇒ I = 2A
Correct Answer: B

11. In a meter bridge at balance condition:

A) No current flows through galvanometer
B) Potential difference across wire is zero
C) Current in both gaps is zero
D) Resistance in both gaps must be equal

View Solution

At balance point galvanometer current becomes zero.
Correct Answer: A

12. Resistivity of a material depends on:

A) Length
B) Area
C) Nature of material
D) Shape

View Solution

Resistivity is material property.
Correct Answer: C

13. Equivalent resistance between opposite corners of a square of equal resistors R is:

A) R
B) 2R
C) R/2
D) R/4

View Solution

Equivalent resistance between opposite corners = R.
Correct Answer: A

14. A battery of emf E and internal resistance r gives maximum power to load when:

A) R = 0
B) R = r
C) R = 2r
D) R = infinity

View Solution

Maximum power transfer theorem: R = r.
Correct Answer: B

15. SI unit of electrical conductivity is:

A) Ωm
B) Ω⁻¹m⁻¹
C) Ω⁻¹m
D) Ωm⁻¹

View Solution

Conductivity = reciprocal of resistivity.
Correct Answer: B

16. In series combination of resistors, current through each resistor is:

A) Different
B) Same
C) Zero
D) Infinite

View Solution

Same current flows in series circuit.
Correct Answer: B

17. The current flowing through a conductor is directly proportional to:

A) Resistance
B) Resistivity
C) Voltage
D) Length

View Solution

Ohm’s law: I ∝ V.
Correct Answer: C

18. A conductor offers resistance due to:

A) Electron collisions
B) Magnetic effect
C) Gravitational effect
D) Nuclear force

View Solution

Resistance arises due to collisions of electrons with ions.
Correct Answer: A

19. Which device converts electrical energy into heat energy?

A) Motor
B) Generator
C) Heater
D) Transformer

View Solution

Electric heater converts electrical energy into heat.
Correct Answer: C

20. Wheatstone bridge is used to measure:

A) Voltage
B) Current
C) Resistance
D) Power

View Solution

Wheatstone bridge measures unknown resistance.
Correct Answer: C

21. Dimensional formula of resistance is:

A) ML²T⁻³A⁻²
B) MLT⁻²
C) ML²T⁻²
D) MT⁻²A⁻¹

View Solution

Resistance dimension is ML²T⁻³A⁻².
Correct Answer: A

22. Which material has highest conductivity?

A) Copper
B) Silver
C) Aluminium
D) Iron

View Solution

Silver has highest electrical conductivity.
Correct Answer: B

23. One kilowatt-hour equals:

A) 3.6×10⁶ J
B) 1000 J
C) 3600 J
D) 36 J

View Solution

1 kWh = 3.6×10⁶ J.
Correct Answer: A

24. Current in metallic conductors is due to flow of:

A) Protons
B) Electrons
C) Neutrons
D) Holes

View Solution

Free electrons move in metallic conductors.
Correct Answer: B

25. A 5Ω resistor and 10Ω resistor are in parallel. Equivalent resistance is:

A) 15Ω
B) 5Ω
C) 3.33Ω
D) 2Ω

View Solution

R = (5×10)/(5+10)=3.33Ω.
Correct Answer: C

26. Internal resistance of an ideal cell is:

A) 1Ω
B) Infinite
C) Zero
D) 10Ω

View Solution

Ideal cell has zero internal resistance.
Correct Answer: C

27. Unit of emf is:

A) Ampere
B) Coulomb
C) Volt
D) Ohm

View Solution

EMF is measured in volt.
Correct Answer: C

28. Power consumed in resistor is maximum when:

A) Current is minimum
B) Voltage is zero
C) Resistance is zero
D) Current is maximum

View Solution

P = I²R. Higher current gives higher power.
Correct Answer: D

29. The reciprocal of resistance is called:

A) Conductance
B) Conductivity
C) Resistivity
D) Current density

View Solution

1/R is conductance.
Correct Answer: A

30. Ammeter is connected in:

A) Parallel
B) Series
C) Both
D) None

View Solution

Ammeter is connected in series.
Correct Answer: B

31. Voltmeter has:

A) High resistance
B) Low resistance
C) Zero resistance
D) Infinite current

View Solution

Voltmeter must have very high resistance.
Correct Answer: A

32. Drift velocity is directly proportional to:

A) Temperature
B) Electric field
C) Resistance
D) Area

View Solution

v ∝ E.
Correct Answer: B

33. If potential difference doubles, current becomes:

A) Half
B) Double
C) Same
D) Four times

View Solution

From Ohm’s law current doubles.
Correct Answer: B

34. SI unit of resistivity is:

A) Ωm
B) Ω/m
C) Ωm²
D) Ω²m

View Solution

Resistivity unit is ohm-meter.
Correct Answer: A

35. A fuse wire has:

A) Low melting point
B) High melting point
C) Zero resistance
D) Infinite conductivity

View Solution

Fuse should melt quickly, so low melting point.
Correct Answer: A

36. Which law explains heating effect of current?

A) Ohm’s law
B) Joule’s law
C) Faraday’s law
D) Lenz’s law

View Solution

Heating effect is given by Joule’s law.
Correct Answer: B

37. Terminal voltage of a cell is maximum when current is:

A) Zero
B) Maximum
C) Infinite
D) Negative

View Solution

V = E − Ir. Maximum when I=0.
Correct Answer: A

38. Which instrument measures current?

A) Voltmeter
B) Galvanometer
C) Ammeter
D) Potentiometer

View Solution

Ammeter measures current.
Correct Answer: C

39. Resistance of a conductor increases with:

A) Increase in area
B) Decrease in length
C) Increase in length
D) Decrease in resistivity

View Solution

R ∝ L.
Correct Answer: C

40. SI unit of electric power is:

A) Joule
B) Watt
C) Volt
D) Coulomb

View Solution

Power unit is watt.
Correct Answer: B

41. A resistor converts electrical energy into:

A) Magnetic energy
B) Heat energy
C) Sound energy
D) Nuclear energy

View Solution

Electrical energy converts mainly into heat.
Correct Answer: B

42. A superconducting material has resistance:

A) Infinite
B) Very high
C) Zero
D) Negative

View Solution

Superconductors have zero resistance.
Correct Answer: C

43. Potential gradient in potentiometer is:

A) Voltage per unit length
B) Current per unit area
C) Resistance per unit length
D) Power per unit length

View Solution

Potential gradient = voltage/length.
Correct Answer: A

44. Current is rate of flow of:

A) Energy
B) Charge
C) Mass
D) Resistance

View Solution

I = dq/dt.
Correct Answer: B

45. Combination of cells in parallel is used to:

A) Increase emf
B) Increase current capacity
C) Decrease emf
D) Increase resistance

View Solution

Parallel combination increases current capacity.
Correct Answer: B

46. Ohmic conductors obey:

A) Boyle’s law
B) Joule’s law
C) Ohm’s law
D) Kirchhoff’s law

View Solution

Ohmic conductors obey Ohm’s law.
Correct Answer: C

47. Which quantity remains constant in parallel combination?

A) Current
B) Resistance
C) Voltage
D) Power

View Solution

Voltage remains same across parallel branches.
Correct Answer: C

48. The SI unit of conductance is:

A) Henry
B) Siemens
C) Tesla
D) Farad

View Solution

Conductance unit is Siemens.
Correct Answer: B

49. The color code of resistor is used to determine:

A) Voltage
B) Current
C) Resistance value
D) Conductivity

View Solution

Color code indicates resistance value.
Correct Answer: C

50. The equivalent resistance of two equal resistors R in parallel is:

A) 2R
B) R
C) R/2
D) R/4

View Solution

Equivalent resistance = R/2.
Correct Answer: C

51. A wire of resistance 4Ω is stretched to 3 times its original length. The new resistance will be:

A) 12Ω
B) 24Ω
C) 36Ω
D) 48Ω

View Solution

Since volume remains constant, R ∝ L²
New resistance = 4 × 3² = 36Ω
Correct Answer: C

52. A 12V battery with internal resistance 1Ω is connected to a 5Ω resistor. Current in circuit is:

A) 1A
B) 2A
C) 3A
D) 4A

View Solution

Total resistance = 5 + 1 = 6Ω
I = 12/6 = 2A
Correct Answer: B

53. A resistor consumes 100W when connected to 200V supply. Its resistance is:

A) 100Ω
B) 200Ω
C) 300Ω
D) 400Ω

View Solution

R = V²/P = 200²/100 = 400Ω
Correct Answer: D

54. Three resistors 2Ω, 3Ω and 6Ω are connected in parallel. Equivalent resistance is:

A) 1Ω
B) 2Ω
C) 3Ω
D) 6Ω

View Solution

1/R = 1/2 + 1/3 + 1/6 = 1
Hence R = 1Ω
Correct Answer: A

55. In a potentiometer experiment, balancing length is 400 cm for 2V cell. For 1.5V cell balancing length is:

A) 100 cm
B) 200 cm
C) 300 cm
D) 350 cm

View Solution

E ∝ l
1.5/2 = l/400 ⇒ l = 300 cm
Correct Answer: C

56. A current of 2A flows for 5 minutes. Total charge passed is:

A) 150 C
B) 300 C
C) 450 C
D) 600 C

View Solution

Q = It = 2 × 300 = 600 C
Correct Answer: D

57. Two resistors of 4Ω and 12Ω are connected in series across 32V. Voltage across 12Ω resistor is:

A) 8V
B) 12V
C) 24V
D) 32V

View Solution

Total resistance = 16Ω
Current = 32/16 = 2A
Voltage across 12Ω = 2×12 = 24V
Correct Answer: C

58. A 220V heater draws 5A current. Power consumed is:

A) 220W
B) 550W
C) 1100W
D) 2200W

View Solution

P = VI = 220 × 5 = 1100W
Correct Answer: C

59. Resistance of a wire becomes half when:

A) Length doubled
B) Area doubled
C) Area halved
D) Resistivity doubled

View Solution

R = ρL/A. Doubling area halves resistance.
Correct Answer: B

60. An electric bulb rated 100W, 200V has resistance:

A) 100Ω
B) 200Ω
C) 400Ω
D) 800Ω

View Solution

R = V²/P = 200²/100 = 400Ω
Correct Answer: C

61. A current of 0.5A flows through a resistor for 2 hours. Charge passed is:

A) 1800 C
B) 2400 C
C) 3600 C
D) 7200 C

View Solution

Q = It = 0.5 × 7200 = 3600 C
Correct Answer: C

62. A resistor dissipates 81W when current is 3A. Resistance is:

A) 3Ω
B) 6Ω
C) 9Ω
D) 12Ω

View Solution

R = P/I² = 81/9 = 9Ω
Correct Answer: C

63. Two equal resistors in series consume 40W. Power consumed by each resistor is:

A) 5W
B) 10W
C) 20W
D) 40W

View Solution

Equal resistors share equal power.
Correct Answer: C

64. If drift velocity doubles, current becomes:

A) Half
B) Double
C) Four times
D) Same

View Solution

I ∝ vd.
Correct Answer: B

65. A 10Ω resistor connected to 20V battery draws current:

A) 0.5A
B) 1A
C) 2A
D) 4A

View Solution

I = V/R = 20/10 = 2A
Correct Answer: C

66. The equivalent resistance of 3Ω and 6Ω in parallel is:

A) 1Ω
B) 2Ω
C) 3Ω
D) 4Ω

View Solution

R = (3×6)/(3+6)=2Ω
Correct Answer: B

67. Energy consumed by 100W bulb in 10 hours is:

A) 0.1 kWh
B) 1 kWh
C) 10 kWh
D) 100 kWh

View Solution

Energy = 100 × 10 = 1000Wh = 1kWh
Correct Answer: B

68. A 2Ω resistor carries 4A current. Heat produced in 5s is:

A) 80J
B) 120J
C) 160J
D) 240J

View Solution

H = I²Rt = 16×2×5 = 160J
Correct Answer: C

69. Two cells each of emf 1.5V are connected in series. Total emf is:

A) 0.75V
B) 1.5V
C) 2V
D) 3V

View Solution

Series emf adds.
Correct Answer: D

70. The resistance of ideal ammeter is:

A) Infinite
B) Very high
C) Zero
D) 1Ω

View Solution

Ideal ammeter has zero resistance.
Correct Answer: C

71. A 60W bulb operated for 5 hours consumes:

A) 0.3 kWh
B) 3 kWh
C) 30 kWh
D) 300 kWh

View Solution

Energy = 60×5 = 300Wh = 0.3kWh
Correct Answer: A

72. Current density increases if:

A) Area increases
B) Current decreases
C) Area decreases
D) Resistivity decreases

View Solution

J = I/A. Smaller area gives larger current density.
Correct Answer: C

73. Two 4Ω resistors in parallel have equivalent resistance:

A) 1Ω
B) 2Ω
C) 4Ω
D) 8Ω

View Solution

Equivalent = R/2 = 2Ω
Correct Answer: B

74. Which material is generally used in fuse wire?

A) Copper
B) Aluminium
C) Lead-tin alloy
D) Silver

View Solution

Fuse wire is lead-tin alloy.
Correct Answer: C

75. Resistance of conductor depends on temperature because:

A) Length changes
B) Area changes
C) Collision frequency changes
D) Charge changes

View Solution

Temperature affects electron collisions.
Correct Answer: C

76. If voltage becomes three times, power becomes:

A) 3 times
B) 6 times
C) 9 times
D) Same

View Solution

P ∝ V², so power becomes 9 times.
Correct Answer: C

77. In parallel combination, equivalent resistance is always:

A) Greater than largest resistance
B) Smaller than smallest resistance
C) Equal to largest resistance
D) Infinite

View Solution

Parallel equivalent is less than smallest resistor.
Correct Answer: B

78. A current of 5A flows through 10Ω resistor. Potential difference is:

A) 2V
B) 10V
C) 50V
D) 100V

View Solution

V = IR = 5×10 = 50V
Correct Answer: C

79. SI unit of electric charge is:

A) Ampere
B) Coulomb
C) Volt
D) Joule

View Solution

Charge is measured in coulomb.
Correct Answer: B

80. A 100Ω resistor connected to 10V battery draws power:

A) 0.1W
B) 1W
C) 10W
D) 100W

View Solution

P = V²/R = 100/100 = 1W
Correct Answer: B

81. Two resistors 5Ω and 15Ω in series have total resistance:

A) 3.75Ω
B) 10Ω
C) 20Ω
D) 75Ω

View Solution

Series resistances add.
Correct Answer: C

82. The unit of current is:

A) Volt
B) Coulomb
C) Ampere
D) Watt

View Solution

SI unit of current is ampere.
Correct Answer: C

83. Which law is based on conservation of energy?

A) Junction law
B) Loop law
C) Ohm’s law
D) Joule’s law

View Solution

Kirchhoff’s loop law is based on conservation of energy.
Correct Answer: B

84. The reciprocal of resistivity is:

A) Conductance
B) Conductivity
C) Resistance
D) Current density

View Solution

Conductivity = 1/resistivity.
Correct Answer: B

85. A 50V source supplies 2A current. Power supplied is:

A) 25W
B) 50W
C) 100W
D) 200W

View Solution

P = VI = 50×2 = 100W
Correct Answer: C

86. A conductor carrying current remains electrically neutral because:

A) Electrons disappear
B) Positive charges also move
C) Net charge remains balanced
D) Resistance becomes zero

View Solution

Total positive and negative charges remain balanced.
Correct Answer: C

87. Electric current through human body can be dangerous because it produces:

A) Magnetism
B) Heating and shock
C) Light only
D) Resistance only

View Solution

Current causes heating and electric shock.
Correct Answer: B

88. One volt is equal to:

A) 1J/C
B) 1C/J
C) 1A/s
D) 1W/A²

View Solution

Volt = Joule/Coulomb.
Correct Answer: A

89. Electric power can also be written as:

A) IV
B) IR
C) VR
D) I/R

View Solution

P = VI.
Correct Answer: A

90. The slope of V-I graph for ohmic conductor gives:

A) Current
B) Voltage
C) Resistance
D) Power

View Solution

Slope = V/I = R.
Correct Answer: C

91. A resistance wire is drawn into thinner wire. Resistance will:

A) Decrease
B) Increase
C) Remain same
D) Become zero

View Solution

Length increases and area decreases, so resistance increases.
Correct Answer: B

92. Which combination is used in household wiring?

A) Series
B) Parallel
C) Mixed only
D) None

View Solution

Household appliances are connected in parallel.
Correct Answer: B

93. The commercial unit of electrical energy is:

A) Joule
B) Watt
C) Kilowatt-hour
D) Volt

View Solution

Commercial unit is kWh.
Correct Answer: C

94. A battery does work by moving:

A) Mass
B) Heat
C) Charge
D) Neutrons

View Solution

Battery supplies energy to move charges.
Correct Answer: C

95. The heating effect of current is proportional to:

A) I
B) I²
C) 1/I
D) √I

View Solution

H ∝ I²Rt.
Correct Answer: B

96. A conductor has zero resistance at:

A) Room temperature
B) High temperature
C) Superconducting state
D) Melting point

View Solution

Superconductors have zero resistance.
Correct Answer: C

97. A wire carries 10C charge in 2s. Current is:

A) 2A
B) 5A
C) 10A
D) 20A

View Solution

I = Q/t = 10/2 = 5A
Correct Answer: B

98. The resistance of ideal voltmeter is:

A) Zero
B) Very low
C) Infinite
D) 1Ω

View Solution

Ideal voltmeter has infinite resistance.
Correct Answer: C

99. The current through a conductor depends upon:

A) Potential difference
B) Resistance
C) Both A and B
D) None

View Solution

Ohm’s law: I = V/R.
Correct Answer: C

100. Kirchhoff’s laws are applicable to:

A) DC circuits only
B) AC circuits only
C) Both AC and DC circuits
D) Magnetic circuits only

View Solution

Kirchhoff’s laws apply to both AC and DC circuits.
Correct Answer: C