What is the fractional error in g calculated from `T = 2 pi sqrt((l)/(g))` ? Given that fractional error in `T` and `l` are `pm x` and `pm y` respectively.

Options

A. `x+y `
B. `x-y`
C. `2x+y`
D. `2x-y`

Answer

C

Explanation

`T = 2pi sqrt((l)/(g)) rArr g = (4pi^(2) l)/(T^(2))`
`(Delta g)/(g) = (Delta l)/(l) + (2Delta T)/(T) = y = 2x`