Question

If delta X is absolute error in measurement of X and delta Y is absolute error in measurement of Y, then maximum absolute error in measurement of difference of X and Y is

(A) + or - ( delta X - delta Y)

(B) + or - ( delta X + delta Y)

(C) + or - delta X / delta Y

​

Answer 1

If ∆X is absolute error in measurement of X and ∆Y is absolute error in measurement of Y.

To find : the maximum absolute error in measurement of difference of X and Y.

solution : here , x = X ± ∆X and y = Y ± ∆Y

so the difference = x - y

= (X ± ∆X) - (Y ± ∆Y)

= X ± ∆X - Y $\mp$ Y

= (X - Y) ± ∆X $\mp$ Y

To get maximum error in the difference of X and Y, we add error of X and Y.

i.e., maximum absolute error in the difference of X and Y = ± (∆X + ∆Y)

Therefore option (B) is correct choice.