The length of a rectangular plate is measured by a meter scale and is found to be ` 10.0 cm`. Its width is measured by vernier callipers as `1.00 cm`. The least count of the meter scale and vernier calipers are `0.1 cm and 0.01 cm` respectively. Maximum permissibe error in area measurement is.

Options

A. `+- 0.02 cm^2`
B. ` +- 0.1 cm^2`.
C. `+- 0.3 cm^(2)`.
D. zero.

Answer

A

Explanation

`A = l xx b`
= `10 xx 1.0 = 10 cm^2`
`(DeltaA)/A=(Deltal)/l+(Deltab)/b`
`:. DeltaA = +-((Deltal)/l+(Deltab)/b) xx A`
= `+- ((0.1)/(10.0)-(0.01)/(1.00))xx 10`
= `+- 0.2 cm^2`.