Question

Two similar bar magnets P and Q, each of magnetic moment $M$, are taken. If P is cut along its axial line and Q is cut along its equatorial line, All the four pieces obtained have

• A. equal pole strength
• B. magnetic moment $\frac{M}{4}$
• C. magnetic moment $\frac{M}{2}$
• D. magnetic moment $M$

Answer 1

The correct option is C magnetic moment $\frac{M}{2}$

If pole strength, magnetic moment and length of each part are $m^{\prime },M^{\prime }$ and $L^{\prime }$ respectively then

$L^{\prime }=\frac{L}{2}$

$\Rightarrow M^{\prime }=\frac{M}{2}$