Question

Measure of two quantities along with the precision of respective measuring instrument is `A=2.5ms^(-1)+-0.5ms^(-1)`,B=0.10s+-0.01s`. The value of AB will be
A. `(0.25+-0.08)m`
B. `(0.25+-0.5)m`
C. `(0.25+-0.05)m`
D. `(0.25+-0.135)m`

Answer 1

Correct Answer - A
`"Given"," " A=2.5 ms^(-1)+-0.5ms^(-1),B=0.10s+-0.01 s`
`" "x=AB=(2.5)(0.10)=0.25m`
`" "(Deltax)/x=(DeltaA)/A+(DeltaB)/B`
`" "=(0.5)/(2.5)+(0.01)/(0.10)=(0.15+0.025)/(0.25)=(0.075)/(0.25)`
`Deltax=0.075=0.08m, "rounding off to two significant figures."`
`AB=(0.025+-0.08)m`