An insulated conductor initially free from charge is charged by repeated contacts with a plate which after each contact is replenished to a charge Q. If q is the charge on the conductor after first operation then the maximum charge which can be given to the conductor is:
Correct answer: D. The maximum charge on the conductor is Q(1 - 1/e)
- A. The maximum charge on the conductor is Q
- B. The maximum charge on the conductor is 2Q
- C. The maximum charge on the conductor is q = Q
- D. The maximum charge on the conductor is Q(1 - 1/e)
Explanation
When an insulated conductor is charged by repeated contacts with a plate replenished to a charge Q, each contact transfers a fraction of the plate's charge to the conductor. The process is iterative, with charge accumulating on the conductor according to the formula: q = Q(1 - (1/e)^n) where n is the number of contacts. As n approaches infinity, the charge on the conductor approaches the maximum of Q(1 - 1/e). Options A, B, and C incorrectly describe or overestimate this process, while Option D correctly describes the asymptotic behavior of the charge accumulation.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
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.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Physics questions like this
Physics is on 16 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Electrostatics questions
In the given circuit, the resistance R has a value that depends on the current. Specifically, R is 20 ohms when I is zero, and the increase in resistance (in ohms) is numerically equal to one-half of the current in amperes. What is the value of current I in the circuit?
A capacitor of capacity C1 = 1µF can with stand the maximum voltage V1 = 16 KV while another capacitor C2 = 2µF can with stand the maximum voltage V2 = 4KV. The maximum voltage of capacitance connected in series will be:
The two spherical shells are at large separation. One of them has a radius of 10 cm and has 1.25 µC charge. The other is of 20 cm radius and has a 0.75 µC charge. If they are connected by a conducting wire of negligible capacity, the charge on the shells are:
An electric charge 10-3 µC is placed at origin (0, 0). Two points A and B are situated at (√2, √2) and (2, 0) respectively. The potential difference between points A and B will be:
Two concentric thin metallic spheres of radii R1 and R2 (R1 > R2) bear charges Q1 and Q2 respectively. Then the potential at radius r between R1 and R2 will be 1/(4πε0) times:
The charge flowing across the cell on closing the switch is equal to: