JEE Main - Capacitance, capacitors and energy stored One Line Questions & Answers

1. A capacitor of 10 µF is charged to 100 V. The energy stored in the capacitor is: — 0.05 J

2. If a capacitor has a capacitance of 1 Farad and is charged to a potential difference of 1 Volt, how much charge does it store? — 1 Coulomb

3. What is the potential difference across a 5 µF capacitor storing 10 mJ of energy? — 20 V

4. What is the capacitance of a capacitor with a charge of 6 µC and a potential difference of 3 V? — 2 µF

5. The energy density in the electric field between the plates of a parallel plate capacitor is given by: — 1/2 ε₀E²

6. What is the maximum energy that can be stored in a 100 µF capacitor rated for 10 V? — 5 mJ

7. What is the capacitance of a capacitor if it stores 0.001 C of charge when the potential difference across it is 100 V? — 10 µF

8. A 1 µF capacitor is charged to 100 V. The charge stored on the capacitor is: — 100 µC

9. A capacitor of 1 µF is charged to 10 V. If the voltage is increased to 20 V, the energy stored increases by a factor of: — 4

10. Two capacitors, 2µF and 4µF, are connected in series. What is the equivalent capacitance? — 4/3 µF

11. Two capacitors, 2µF and 4µF, are connected in parallel. What is the equivalent capacitance? — 6µF

12. The capacitance of a capacitor is defined as the ratio of the charge on one of its conductors to the: — Potential difference between the plates

13. A capacitor with capacitance C is charged to a voltage V. If the voltage is increased to 2V, the stored energy becomes: — 4 times the original energy

14. In a parallel plate capacitor, if the permittivity of the dielectric material is ε, the capacitance is given by C = εA/d. If a vacuum is replaced by a material with dielectric constant k, the capacitance becomes: — Ck

15. The maximum charge a capacitor can hold without breakdown is determined by its: — Dielectric strength

16. What is the effect of increasing the thickness of the dielectric between the plates of a parallel plate capacitor, assuming the dielectric constant remains the same? — Capacitance decreases

17. Two capacitors C1 and C2 are connected in series. The equivalent capacitance Ceq is given by: — 1/Ceq = 1/C1 + 1/C2

18. Which of the following is NOT a type of capacitor? — Inductor capacitor

19. Which of the following statements is true for capacitors in parallel? — Voltage across each capacitor is the same

20. Which of the following statements is true for capacitors in series? — Charge is the same on each capacitor

21. A variable capacitor is used in tuning circuits because its capacitance can be: — Continuously changed

22. The ability of a dielectric material to reduce the electric field between the plates of a capacitor is measured by its: — Dielectric constant

23. The capacitance of a parallel plate capacitor is given by C = ε₀A/d, where A is the area of the plates and d is the distance between them. If the distance between the plates is doubled, the capacitance will: — Halve

24. If the area of the plates of a parallel plate capacitor is doubled, its capacitance will: — Double

25. If the voltage across a capacitor is doubled, the energy stored in it will: — Become four times

26. If the distance between the plates of a parallel plate capacitor is halved, while keeping the charge constant, the potential difference between the plates will: — Double

27. Which type of capacitor is suitable for high-frequency applications and has a stable capacitance value? — Ceramic capacitor

28. What is the unit of charge? — Coulomb

29. The unit of energy stored in a capacitor is: — Joule

30. What is the unit of dielectric constant? — Dimensionless

31. If a capacitor is charged and then discharged, the energy stored is dissipated as: — Heat

32. If a capacitor is charged by a battery and then disconnected, and the plates are moved farther apart, the potential difference across the capacitor will: — Increase

33. If a capacitor is charged by a battery and remains connected, and the plates are moved farther apart, the charge on the capacitor will: — Decrease

34. The capacitance of a parallel plate capacitor filled with a dielectric material is 10 µF. If the dielectric is removed, the capacitance will: — Decrease

35. When a dielectric is inserted into a charged capacitor disconnected from the battery, the electric field between the plates: — Decreases

36. When a dielectric material is inserted between the plates of a charged capacitor (disconnected from the source), the capacitance: — Increases

37. A capacitor is essentially a device to increase the electrical energy storage capacity of a circuit by: — Increasing capacitance

38. What happens to the capacitance of a parallel plate capacitor if a dielectric material is introduced between the plates? — It increases

39. The dielectric constant of a material is always: — Greater than or equal to 1

40. Dielectric strength is the maximum electric field a dielectric material can withstand without: — Becoming a conductor

41. A capacitor is a device used to store: — Electrical energy

42. What is the work done to move a charge q from infinity to a point where the potential is V? — qV

43. The capacitance of a spherical capacitor of radius R is proportional to: — R

44. When capacitors are connected in parallel, the total capacitance is: — The sum of individual capacitances

45. Electrolytic capacitors are polarized and must be connected with the correct polarity. This is because: — Their dielectric layer is very thin and can be damaged by reverse voltage

46. The energy stored in a capacitor is given by the formula: — U = 1/2 CV²

47. The energy stored in a capacitor can also be expressed as: — U = Q²/C

48. If two capacitors C1 and C2 are connected in series and charged by a voltage V, the voltage across C1 is given by: — V * C2 / (C1 + C2)

49. If two capacitors C1 and C2 are connected in parallel and charged by a voltage V, the charge on C1 is given by: — V * C1

50. What is the unit of capacitance in the SI system? — Farad

Capacitance, capacitors and energy stored - One Line Questions