JEE Mains · Physics · STD 12 - 5. Magnetism and matter
A bar magnet is demagnetized by inserting it inside a solenoid of length \(0.2\, m\), \(100\, turns\), and carrying a current of \(5.2\, A\). The coercivity of the bar magnet is.....\(A/m\)
- A \(285\)
- B \(2600\)
- C \(520\)
- D \(1200\)
Answer & Solution
Correct Answer
(B) \(2600\)
Step-by-step Solution
Detailed explanation
\(\mathrm{B}=\mu_{\mathrm{o}} \mathrm{H} \quad ; \quad \mu_{\mathrm{o}} n i=\mu_{\mathrm{o}} \mathrm{H}\) \(\frac{100}{0.2} \times 5.2=\mathrm{H}\) \(\mathrm{H}=2600 \,\mathrm{A} / \mathrm{m}\)
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