Time period of oscillating magnetic needle is T=2πMBI
=2π6.7×10−2×0.017.5×10−6sec
=0.6647sec
Time for oscillations, t=10T=6.647sec=6.65sec
JEE Main 2017 — Physics Electromagnetism
A magnetic needle of magnetic moment 6.7×10−2Am2 and moment of inertia 7.5×10−6kgm2 is performing simple harmonic oscillations in a magnetic field of 0.01T. Time taken for 10 complete oscillations is:
Held on 2 Apr 2017 · Verified 6 Jul 2026.
8.76s
6.65s
8.89s
6.98s
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