An iron bar of length $L$ has magnetic moment $M$. It is bent at the middle of its length such that the two arms make an angle $60^{\circ}$ with each other. The magnetic moment of this new magnet is :
$\frac{M}{2}$
$2 M$
$\frac{M}{\sqrt{3}}$
$M$
The ultimate individual unit of magnetism in any magnet is called
Magnetic field intensity is defined as
A closely wound solenoid of $800$ turns and area of cross section $2.5 \times 10^{-4} \;m ^{2}$ carries a current of $3.0\; A .$ Explain the sense in which the solenoid acts like a bar magnet. What is its associated magnetic moment?
Two identical bar magnets are fixed with their centres at a distance $d$ apart. A stationary charge $Q$ is placed at $P$ in between the gap of the two magnets at a distance $D$ from the center $O$ as shown in the figure. The force on the charge $Q$ is
Write the equation of dipole moment of magnet in the form of electric current.