Question

An experiment measures quantities a, b and c and X is calculated from `X= ab^(2)//c^(3)`. If the percentage error in a, b and c are `pm 1%, pm 3% and pm 2%` respectively, the percentage error in X will be-
A. `pm 13 % `
B. `pm 7 % `
C. `pm 4 % `
D. `pm 1 %`

Answer 1

Correct Answer - A
`X = ab^(2) //c^(3) rArr (Delta X)/(X) = (Delta a )/(a) pm 2 (Delta b)/(b) pm 3 (Delta c)/(c )`
`(Delta X)/(X) xx 100 = pm 1 % pm 2 xx 3% pm 3 xx 2% = pm 13 % `