Question

The dielectric constant of a metal is:
A. $\infty $
B. $0$
C. $1$
D. None

Answer 1

Hint: Metal is a good conductor of electrons and hence charges.

Complete step by step solution:
Dielectric constant (K) of a medium may be defined as the ratio of the force between two charges placed at a certain distance apart in air to the force between the same two charges placed the same distance apart in that medium.
It is also called as relative permittivity of the medium with respect to the vacuum.
Metal is a good conductor. So its dielectric constant is infinity.
\[{K_{metal}}\; = \;\,\infty \]
Metal is a good conductor and it easily allows charges to conduct and hence the permittivity will increase and its dielectric constant will become infinity.

So the correct option is (A), $\infty $.

Additional Information:
1. Unit of charge is the coulomb where the smallest charge possible is the charge on an electron or proton \[1.6 \times {10^{ - 19}}C\].
2. One coulomb is that charge which will repel an equal and similar charge with a force of \[9 \times {10^9}\,N\], when placed in a vacuum or air at a distance of one metre from it.

Note: (i) In electrostatic cgs system , the unit of charge is known as electrostatic unit of charge (e.s.u. of charge).It is also called as stat coulomb.(stat C)
\[1C = 3{\text{ }}x{\text{ }}{10^9}\] stat C
(ii) In the electromagnetic cgs system , the unit of charge is known as the electromagnetic unit of charge (e.m.u. of charge).
\[1C = 1/10\] e.m.u. of charge