⚛️ Physics · Electrostatic Potential and Capacitance · NEET & JEE

Two metal spheres of different radii are connected by a long thin wire. Surface charge density:

Answer: Greater on smaller sphere.

A Same on both
B Greater on larger sphere
C Greater on smaller sphere
D Zero on both

Correct answer: C. Greater on smaller sphere

Explanation: Connected spheres have same potential. V = kQ/R = k(sigma x 4piR<sup>2</sup>)/R = 4pi sigma kR. So sigma proportional to 1/R. Smaller sphere has higher surface charge density.

Radial electric field lines and concentric red equipotential lines around a point charge (an electron), with field lines pointing inward

Field lines (radial) and equipotential lines (concentric circles) of a point charge. Equipotential surfaces are always perpendicular to the field lines. Image: Sjlegg, Public Domain, via Wikimedia Commons.

Concept context

Electric potential, equipotential surfaces, potential energy of charge systems, conductors, dielectrics, capacitors, combinations, and energy storage.

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Two metal spheres of different radii are connected by a long thin wire. Surface charge density:

Concept context

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