A bar magnet of length 3 cm has a point A and B along axis at a distance of 24 cm and 48 cm on the opposite ends. Ratio of magnetic fields at these points will be

Question

A bar magnet of length 3 cm has a point A and B along axis at a distance of 24 cm and 48 cm on the opposite ends. Ratio of magnetic fields at these points will be (A) 8 (B) 3 (C) 4 (D) 1 / 2 √2

Tardigrade Admin · Accepted Answer

Here, 2 l=3 cm , d1=24 cm and d2=48 cm As, the magnet is short, (B1/B2)=(d23/d13) =((48 cm /24 cm ))3=8

Q. A bar magnet of length $3 c m$ has a point $A$ and $B$ along axis at a distance of $24 c m$ and $48 c m$ on the opposite ends. Ratio of magnetic fields at these points will be

8

3

4

$1/2 2$

Here, $2 l = 3 c m, d_{1} = 24 c m$ and $d_{2} = 48 c m$
As, the magnet is short, $\frac{B _{1}}{B _{2}} = \frac{d _{2}^{3}}{d _{1}^{3}}$
$= (\frac{48 c m}{24 c m})^{3} = 8$

Q. A bar magnet of length 3cm has a point A and B along axis at a distance of 24cm and 48cm on the opposite ends. Ratio of magnetic fields at these points will be

8

3

4

1/22​

Here, 2l=3cm,d1​=24cm and d2​=48cm As, the magnet is short, B2​B1​​=d13​d23​​ =(24cm48cm​)3=8

Q. A bar magnet of length $3 c m$ has a point $A$ and $B$ along axis at a distance of $24 c m$ and $48 c m$ on the opposite ends. Ratio of magnetic fields at these points will be

$1/2 2$

Here, $2 l = 3 c m, d_{1} = 24 c m$ and $d_{2} = 48 c m$
As, the magnet is short, $\frac{B _{1}}{B _{2}} = \frac{d _{2}^{3}}{d _{1}^{3}}$
$= (\frac{48 c m}{24 c m})^{3} = 8$