Which of the following types of motion are oscillatory?

i.a diving board when used by a diver.
ii. the motion of the balance wheel of a wrist watch.
iii. the motion of the turn-table of a record player.
iv. the motion of the center of a ten kobo piece as it rolls down an inclined plane.
v. the motion of the needle of a D.C. ammeter into which a low A.C. current is passed

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