Question

Magnet A has twice the magnetic field strength of magnet B and pulls on magnet B with a force of 100 N. The amount of force that magnet A exerts on magnet B isA) about 50 N.B) exactly 100 N.C) more than 100 N.D) not enough information

Answer 1

The force exerted by the magnetic in terms of the magnetic field is,

$F\propto B$

Where B is the magnetic fied strength and F is the force.

Thus, if the magnetic A has twice magnetic field strength than the magnet B,

Then,

$B_A=2B_B$

Thus, the force exerted by the magnet B is,

$\begin{gathered} F_B\propto B_B \\ F_B\propto\frac{B_A}{2} \\ F_B=\frac{F_A}{2} \\ F_B=\frac{100}{2} \\ F_B=50\text{ N} \end{gathered}$

Thus, the force exerted by the magnet B on magnet A is 50 N.

The force exerted by the magnet A exerts on the magnet B is exactly 100 N as given.

Hence, the option B is the correct answer.