Four metal conductors having different shapes 1. a sphere
2. cylindrical
3. pear
4. lightning conductor
are mounted on insulating stands and charged. The one which is best suited to retain the charges for a longer time is

Options

A. 1
B. 2
C. 3
D. 4

Answer

a

Explanation

In case of spherical metal conductor the charge quickly Spreads uniformly over the entire surface because of which charges stay for longer time on the spherical surface. While in case of non-spherical surface, the charge concentration is different at different points due to which the charges do not stay on the surface for longer time. Like in pear shaped conductor the charge more concentrated on curved regions and less concentrated on the straight regions. If the small end is made more pointed, the density will increase at the end.