A potential difference of V = `(20pm 1)` volt is applied across a resistance of `(8pm2)` ohm. Calculate the current with error limits.

Explanation

We know from Ohm.s law V = `I`R or, `I = (V)/(R )`
Current without error limit is `I= (20)/(8) =2.5` A
Next the maximum fractional error in `I` is
`(DeltaI)/(I)=(DeltaV)/(V)+(DeltaR)/(R)=(1)/(20)+(2)/(8)`
or, `(DeltaI)/(I)= 0.05 +0.25 = 0.30`
`:. DeltaI = 0.30xx2.5 = 0.75 `A
`:.` The current with error limits is
`(2.5 pm 0.75)` A or ,(`2.5 pm 0.8)` A