Medium INTEGER +4 / -1 PYQ · JEE Mains 2021

The value of aluminium susceptibility is 2.2 $\times$ 10$-$5. The percentage increase in the magnetic field if space within a current carrying toroid is filled with aluminium is ${x \over {{{10}^4}}}$. Then the value of x is _________________.

Answer (integer) 22

Solution

$B = \mu .(H + I)$<br><br>$B = \mu .H\left( {1 + {1 \over H}} \right)$<br><br>$B = {B_0}(1 + x)$<br><br>$B - {B_0} = {B_0}x$<br><br>${{B - {B_0}} \over {{B_0}}} = x$<br><br>${{B - {B_0}} \over {{B_0}}} \times 100 = 100x$<br><br>$= 2.2 \times {10^{ - 3}} = {{22} \over {{{10}^4}}}$

About this question

Subject: Physics · Chapter: Magnetism · Topic: Bar Magnet and Magnetic Field

This question is part of PrepWiser's free JEE Main question bank. 52 more solved questions on Magnetism are available — start with the harder ones if your accuracy is >70%.

Drill 25 more like these. Every day. Free.

PrepWiser turns these solved questions into a daily practice loop. Chapter-wise drills, full mocks, AI doubt chat. No auto-renew.

Start free →