Electrostatics

Q1 · Electrostatics · MEDIUM

A thin non-conducting ring of radius R carries a total charge Q distributed uniformly. A point charge q is placed at the center of the ring. If the ring is slightly displaced along its axis by a small distance x (x << R), the restoring force on the ring is approximately:

Q2 · Electrostatics · MEDIUM

Two identical metallic spheres of radius R are placed such that their centers are separated by distance d (d >> R). One sphere has charge +Q and the other has charge -3Q. They are connected by a thin wire and then disconnected. The force between them after disconnection is:

Q3 · Electrostatics · MEDIUM

Three identical charges q are placed at the vertices of an equilateral triangle of side a. The work done in bringing another charge q from infinity to the centroid of the triangle is:

Q4 · Electrostatics · MEDIUM

Three identical charges q are placed at the vertices of an equilateral triangle of side a. A charge Q is placed at the centroid of the triangle such that the system is in equilibrium. The value of Q is:

Q5 · Electrostatics · MEDIUM

Two identical conducting spheres carry charges +Q and –3Q respectively. They are brought into contact and then separated. The final charge on each sphere is: