Find the percentage error in calculating the surface area of a cubical box if an error of 1% is made in measuring the lengths of edges of the cube.

Options

A. 1%
B. 2%
C. 3%
D. None of these

Answer

B

Explanation

Let `a` is the side of the cube.
Surface area of the cube, `S = 6a^2`

Now, `(dS)/(da) = 12a`

`=>dS = 12a *da`

It is given that `da = 1%` of `a= a/100`

`=>dS = 12a*a/100 = 2/100*6a^2`

`=>dS = 2/100*S`

`=>dS = 2%` of `S`

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