A magnetic needle of magnetic moment 6.7×10−2 Am2 and moment of inertia 7.5×10−6 kg m2 is performing simple harmonic oscillations in a magnetic field of 0.01 T. Time taken for 10 complete oscillations is :
6.65 s
8.89 s
6.98 s
8.76 s
As we learnt in
Time period of Oscillating Bar Magnet -
- wherein
I = Moment of Inertia of short bar magnet
M - Mass of bar magnet
Hence T = 6.65 s
Option 1)
6.65 s
Correct
Option 2)
8.89 s
Incorrect
Option 3)
6.98 s
Incorrect
Option 4)
8.76 s
Incorrect
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