The figure below shows three circular arcs, each of radius R and total charge as indicated. The net electric potential at the center of curvature is:
Correct answer: A. The net electric potential is proportional to the sum of the charges divided by the radius R.
- A. The net electric potential is proportional to the sum of the charges divided by the radius R.
- B. The net electric potential is zero due to symmetry.
- C. The net electric potential depends only on the largest charge.
- D. The net electric potential is inversely proportional to the sum of the charges.
Explanation
The net electric potential at the center of curvature due to each arc is the sum of potentials from each arc. For a single arc with charge Q and radius R, the potential is given by V = kQ/R. Since potential is a scalar, the total potential is the algebraic sum of the potentials due to each arc. Hence, the correct approach is to calculate the potential due to each arc and sum them up.Option A is correct because it considers the contribution of all charges, while Option B incorrectly assumes symmetry leads to zero potential. Option C is incorrect as it ignores the contributions of smaller charges, and Option D is incorrect as it misrepresents the relationship between potential and charge.
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
Two charges Q1 and Q2 C are placed at points R and S. A third charge Q3 C is moved from point R to S along the circular path. Change in potential energy of the charge is:
An assembly of charges, +q, -q, +q, -q ........ are placed at distance x = 1m, x = 2m, x = 4m, x = 8m and so on, from the origin, in a plane. The potential at x = 0, due to the charges would be:
Two identical capacitors have the same capacitance C. One of them is charged to potential V1 and the other to V2. The negative ends of the capacitors are connected together. When the positive ends are also connected, the decrease in energy of the combined system is:
Two points P and Q are maintained at the potentials of 10V and -4V respectively. The work done in moving 100 electrons from P to Q is:
On moving a charge of 2C from a point A where potential is +12V to a point B where potential is -12V, the work done is:
Three charges -q, Q and -q are placed at equal distances on a straight line. If the potential energy of the system of three charges is zero, then what is the ratio of Q:q?