Question

which of the following relation will hold good?
a. e = ε d
b. d = μ h
c. b = μ h
d. b = ε e

Explanation:

To determine the correct relation, we recall the fundamental electromagnetic field relationships:

• The electric displacement field \( D \) is related to the electric field \( E \) by \( D=\varepsilon E \), where \( \varepsilon \) is the permittivity of the medium.
• The magnetic flux density \( B \) is related to the magnetic field strength \( H \) by \( B = \mu H \), where \( \mu \) is the permeability of the medium.

Now let's analyze each option:

• Option a: The correct relation is \( D=\varepsilon E \), not \( E=\varepsilon D \), so this is incorrect.
• Option b: The correct relation is \( B=\mu H \), not \( D = \mu H \) (since \( D \) is electric and \( \mu \) is magnetic permeability), so this is incorrect.
• Option c: \( B=\mu H \) is the correct relation between magnetic flux density \( B \) and magnetic field strength \( H \), so this is correct.
• Option d: There is no such relation as \( B=\varepsilon E \); \( \varepsilon \) is related to electric fields and \( \mu \) to magnetic fields, so this is incorrect.

Answer:

c. \( B = \mu H \)