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An electric motor winds 200 turns of a t...

An electric motor winds 200 turns of a thin coper wire on a unifrom of diameter 10 cm, in 2 seconds.then the length of the wire that is wound over the rod in one second is _______ m.

A

30

B

`10pi`

C

`20pi`

D

None of these

Text Solution

Verified by Experts

The correct Answer is:
B
The number of turns wound over the rod = 200.
The diameter of the rod, (d) = 10 cm.
R = 5 cm = 0.05 m
The time taken to wind, (t) = 2 s
The length of the wire wound in one second = `("distance")/("time")`
= `(200xx2pir)/2=(200xx2pixx0.05)/2=10pim`.
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