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

Options

A. `pm0.2 cm^(2)`
B. `pm 0.1 c m^(2)`
C. `pm 0.3 cm^(2)`
D. zero

Answer

A

Explanation

A=lb=10.0x 1.00=10.00
`(DeltaA)/A=(Deltal)/l+(DeltaB)/b`
`(DeltaA)/10.00=0.1/10.0+0.01/1.00`
`rArr DeltaA=10.00(1/100+1/100)=10.00(2/100)=pm0.2 cm^(2)`