Question

What is the magnetic moment of a current-carrying circular coil if the radius of the circular coil is 'R' and magnetic induction at the center is 'B'?

Options

• `(2pi "BR"^3)/mu_0`

• `(pi "BR"^3)/mu_0`

• `(pi "B"^2"R"^2)/mu_0`

• `(pi "B"^2 "R"^3)/mu_0`

Answer 1

`(2pi "BR"^3)/mu_0`

Explanation:

`"M" = "A"  "i" = pi "R"^2 "i"`

`"B" = (mu_0 "i")/(2 "R")`

`= pi "R"^2 ((2"RB")/mu_0)`

`= (2pi "BR"^3)/mu_0`