A capacitor "C" has a charge Q". The actual charges on its plates are:
Correct answer: A. Q, -Q
- A. Q, -Q
- B. Q/2, -Q/2
- C. Q, Q
- D. Q, 0
Explanation
A capacitor is a device that stores electrical energy in an electric field, created by two conductive plates separated by an insulator. When a capacitor has a charge 'Q', it means one plate has a charge of '+Q' and the other has a charge of '-Q'. This arrangement ensures that the net charge of the system is zero, as required by the conservation of charge. Option A is correct because it reflects this fundamental property of capacitors. Options B and D suggest unequal or no charges on the plates, which is incorrect. Option C suggests the same charge on both plates, which defies the nature of capacitors.
Last updated
About Electrostatics
Electrostatics describes forces between charges through Coulomb's law, electric fields and field intensity, then uses electric potential to measure energy per unit charge. Capacitors store charge and electrical energy, with capacitance depending on geometry and dielectric material, not simply on the amount of charge present.
Practise Electrostatics
831 free Electrostatics MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Physics questions like this
Physics is on 13 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
1/C_eq = 1/C_1 + 1/C_2 + 1/C_3 + ... + 1/C_n
1 N/C equals to:
1 volt x 1 ampere is equal to:
10 V potential difference is applied across the plate of the 1 µF capacitor. What is the energy stored in the capacitor?
12 J work is to be done against an existing electric field to take a charge of 0.01C from A to B. Find the potential difference between B and A: