The length and breadth of a rectangular sheet are 16.2 cm and 10.1cm, respectively. The area of the sheet in appropriate significant figures and error is

Options

A. `164 +- 3 cm^2`
B. `163.62 +-2.6 cm^2`
C. `163.6 +- 2.6 cm ^2 `
D. `163.62 +- 3 cm^2`

Answer

(a)

Explanation

Here, `I= (16.2 +- 0.1)cm , b= (10.1 +- 0.1) cm , A =I xx b = 16.2xx10.1 = 163.62`
Rounding off to three significant digits, `A = 164 cm^2`
`(DeltaA)/(A) = ((DeltaI)/(I) +(Deltab)/(b)) = (0.1)/(16.2) + (0.1)/(10.1) = (1.01 + 1.62)/(16.2xx10.1)`
`DeltaA = 2.63`
Rounding offf to one significant figure, `DeltaA = 3 cm^2 :. A = (164 +- 3) cm^2`