A partical of mass `m` is attached to a massless string of length `l` and is oscillating in a vrtical plane with the other end of the string fixed to a rigid support. The tension in the string at a certain instant is `T=kmg` .

Options

A. k can never be geaater than 1
B. k can never be less than 1
C. k can never be equal than 1
D. k can never be geaater than 3

Answer

D

Explanation

Maxmum tension will be at lowest point:
`T-mg=(mv^(2))/(r)` implies `T=mg+(mv^(2))/(l)`
`v_(max)=sqrt(2gl)` larr Condition for collision.
`T_(max)=mg+(m(sqrt(2gl)^(2)))/(l)=3mg` .