Assertion : A thin aluminiumdisc spinningfreely about a centralpivot is quickly brought to restwhen placedbetween the poles of a strong U-shaped magnet . Reason : A current induced in a disc rotating in a magnetic field produces aforce whichtends to oppose the disc's motion .

Assertion : A thin aluminiumdisc spinningfreely about a centralpivot i

1.	Assertion : A thin aluminiumdisc spinningfreely about a centralpivot is quickly brought to restwhen placedbetween the poles of a strong U-shaped magnet . Reason : A current induced in a disc rotating in a magnetic field produces aforce whichtends to oppose the disc's motion .
Answer» If both the assertion and reason are true statement andreason is CORRECT explanation of the assertion . If both the assertion and reason are true statement but reason is not a correct explanation of the assertion . If the assertion is true but the reason is a false statement. If both assertion and reason are false statements. Solution :This effect is dueto the production of 'eddy CURRENTS' in the aluminium DISC. They are PRODUCED due to the motion of disc in magneticfield.According to Lenz's law they oppose this motion ( which is the CAUSE of their production ) and eventually bring the disc to a stop .

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Assertion : A thin aluminiumdisc spinningfreely about a centralpivot is quickly brought to restwhen placedbetween the poles of a strong U-shaped magnet . Reason : A current induced in a disc rotating in a magnetic field produces aforce whichtends to oppose the disc's motion .

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