The free space inside a current carrying toroid is filled with a material of susceptibility $2 \times 10^{-2}$. The percentage increase in the value of magnetic field inside the toroid will be
Solution
The magnetic susceptibility ($\chi_m$) of a material is the measure of how much the material becomes magnetized in response to an external magnetic field. When the material is placed in a magnetic field, the net magnetic field ($B$) inside the material is the sum of the external magnetic field ($B_0$) and the field produced by the material itself ($B_{material}$). This relationship can be expressed as :
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$B = B_0 + B_{material}$
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Magnetic susceptibility is related to the relative permeability ($\mu_r$) of the material :
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$\mu_r = 1 + \chi_m$
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The magnetic field inside the toroid can be calculated using the following formula :
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$B = \mu_0 \mu_r H$
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where $\mu_0$ is the permeability of free space, $\mu_r$ is the relative permeability of the material, and $H$ is the magnetic field strength.
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Now, let's consider the percentage increase in the magnetic field when the material is placed inside the toroid. The initial magnetic field ($B_0$) is given by :
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$B_0 = \mu_0 H$
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After the material is placed inside the toroid, the magnetic field becomes :
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$B = \mu_0 \mu_r H = \mu_0 (1 + \chi_m) H$
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The percentage increase in the magnetic field can be calculated as :
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$$\frac{B - B_0}{B_0} \times 100\% = \frac{\mu_0 (1 + \chi_m) H - \mu_0 H}{\mu_0 H} \times 100\%$$
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Substitute the value of $\chi_m = 2 \times 10^{-2}$ :
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$$\frac{B - B_0}{B_0} \times 100\% = \frac{(1 + 2 \times 10^{-2}) - 1}{1} \times 100\% = 2\%$$
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Thus, the percentage increase in the value of the magnetic field inside the toroid is 2%.
About this question
Subject: Physics · Chapter: Magnetism · Topic: Bar Magnet and Magnetic Field
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