A short magnet makes 40 oscillations per minute when used in an oscillation magnetometer at a place where the earth’s horizontal magnetic field is 25 μT. Another short magnet of magnetic moment 1.6 A m 2 is placed 20 cm east of the oscillating magnet. Find the new frequency of oscillation if the magnet has its north pole (a) towards north and (b) towards south.

A short magnet makes 40 oscillations per minute when used in an oscillation magnetometer at a place where the earth’s horizontal magnetic field is 25 μT. Another short magnet of magnetic moment 1.6 A m² is placed 20 cm east of the oscillating magnet. Find the new frequency of oscillation if the magnet has its north pole
(a) towards north and

(b) towards south.

Given, v₁ =40oscillation/min

M of second magnet =1.6Am²

(a) for north pole facing north

,

⇒

γ₂ = 17.88 = 18 oscillation/min

(b) for north pole facing south

,

⇒

γ₂= 53.6656 = 54 oscillation/min

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