Physics

Electric Field and PotentialThree charged conducting metal spheres of radius R₁, R2 and R3 are connected together by very thin wires and they are separated by large distances from each other. If R₁ < R₂ < R3, at equilibrium, which of the following sets of relations involving the electric field strength E generated by a sphere at a point just outside the surface, its potential V and its charge Q must hold between the spheres ?
V₁ V₂ V3, E₁ < E₂ < E3, Q1 < Q2 < Q3
V₁ = V₂ = V3, E₁> E2> E3, Q₁ < Q2 Q3
V₁ < V₂ <V3, E₁ < E2 < E3, Q₁ = Q₂ = Q3
V₁ > V₂ V3, E₁ < E₂ < E3, Q1 > Q₂ > Q3

Physics

Electric Field and PotentialTwo insulated charged copper spheres A and B have their centres separated by a distance of 50 cm. What is the mutual force of electrostatic repulsion if the charge on each is 6.5 × 10^-7 C? The radii of A and B are negligible compared to the distance of separation.
(b) What is the force of repulsion if each sphere is charged double the above amount, and the distance between them is halved?

Physics

Electric Field and PotentialSelect all the true statements about kinetic energy (KE) and potential energy (PE) from electric fields. Use your knowledge of gravitational fields to help you select.
A. If two positively charged objects are pushed closer together, the system of the objects and fields gains PE.
B. When a charged particle is accelerated by an electric field along field lines, it loses PE and gains KE.
C. A charged object has KE because of its position in an electric field.

Physics

Electric Field and PotentialA -8.0μC charge is located 0.45 m to the left of a +6.0-µC charge. What is the magnitude and direction of the electrostatic force on the positive charge?
A. 1.1 N, to the right
B. 2.1 N, to the left
C. 4.4 N, to the right
D. 1.1 N, to the left
E. 2.1 N, to the right