A force F is applied in a square plate of length L . If the percentage error in the determination of L is 3% and in F in 4% then permissible error in the calculation of pressure is

Options

A. `13%`
B. `10%`
C. `7 %`
D. `12 %`

Answer

B

Explanation

Given
Percentage error in length = 3%
We know that
Pressure , `P = F/A`
Area of square `= (L)^2`
` P= (F)/(L^2)`
`(Delta P)/(P) = ( Delta F)/( F ) + ( 2 Delta L)/(L) `
` (( Delta P)/( P) xx 100 ) = (( Delta F) /( F) xx 100) + 2 (( Delta L) /(L) xx 100 )`
` = 4% + 2(3%) = 10% `