A uniform chain of length L hangs partially from table and held in equilibrium by friction. If greatest length of chain that hangs without slipping is l then the coefficient of friction between chain and table is

Options

A. L
B. `1/(L+l)`
C. `l/(L-l)`
D. `l/(L+l)`

Answer

c

Explanation

Mass of the chain placed on the table =(L-1)m
Where, m-Mass per unit length of chain
Force due to hanging part,
Coefficient of friction, mu=FIR
where ,R normal reaction of table=(l-1)mg
`mu=lmg/(L-l)mg=l/(L-l)`