Following figures show the arrangement of bar magnets in different configurations. Each magnet has magnetic dipole moment (m). Which configuration has highest value of magnetic dipole moment?

Options

A. A
B. B
C. C
D. D

Answer

C

Explanation

Net magnetic moment
`m = sqrt(m_(1)^(2) + m_(2)^(2) + 2m_(1)m_(2) cos theta)`
`m_(1) = m_(2) = m` will be maximum if `cos theta` is maximum `theta` will be maximum when `theta` will be minimum.
`therefore theta = 30^(@)`