Someone is using a scissors to cut a wire of circular cross section and negligible weight.&nbsp

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4-2.Friction

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Someone is using a scissors to cut a wire of circular cross section and negligible weight. The wire slides in the direction away from the hinge until the angle between the scissors blades becomes $2 \alpha$. The friction coefficient between the blades and the wire, is :-

A

$\sqrt {1-tan \alpha}$

B

$2cos \alpha$

C

$tan \alpha$

D

$2\, tan \alpha$

Solution

$f \cos \alpha=N \sin \alpha$

$\mu \mathrm{N} \cos \alpha=\mathrm{N} \sin \alpha$

$\tan \alpha=\mu$

Standard 11

Physics

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