Concept explainers
(a)
The magnetic field at the center of the sphere.
(a)
Answer to Problem 74CP
The magnetic field at the center of the sphere is
Explanation of Solution
Consider the sphere as being built up by little spinning ring element of radius
Write the equation for the charge on each ring.
Here,
Write the equation for the current through each ring.
Here,
Substitute
Write the expression for the magnetic field at a distance
Substitute
Solve equation (V) further.
Solve equation (VI) further to find
Conclusion:
Therefore, the magnetic field at the center of the sphere is
(b)
The magnetic moment of the sphere.
(b)
Answer to Problem 74CP
The magnetic moment of the sphere is
Explanation of Solution
Write the expression for the magnetic moment by the ring.
Here,
Substitute
Integrate equation (VI) to find
Solve equation (VII) further.
Conclusion:
Therefore, the magnetic moment of the sphere is
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Chapter 30 Solutions
Bundle: Physics for Scientists and Engineers with Modern Physics, Loose-leaf Version, 9th + WebAssign Printed Access Card, Multi-Term
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