COMEDK · Physics · 20. Magnetic Properties of Matter
Find the pole strength of a magnet of length \(2 \mathrm{~cm}\), if the magnetic field strength \(B\) at distance \(10 \mathrm{~cm}\) from the centre of a magnet on the axial line of the magnet is \(10^{-4} \mathrm{~T}\).
- A \(5 \times 10^{-2} \mathrm{~Am}\)
- B \(100 \mathrm{~Am}\)
- C \(1 \times 10^{-4} \mathrm{~Am}\)
- D \(25 \mathrm{~Am}\)
Answer & Solution
Correct Answer
(D) \(25 \mathrm{~Am}\)
Step-by-step Solution
Detailed explanation
The magnetic field \(B\) on the axial line of a short magnet at a distance \(d\) from its centre is given by the formula \(B = \dfrac{\mu_0}{4\pi} \dfrac{2Md}{(d^2 - l^2)^2}\), where \(M\) is the magnetic dipole moment, \(2l\) is the length of the magnet, and \(d\) is the…
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