Question

A piece of iron rod was measured and found to be 120cms. But the actual value of the wood is 123cms. Find the relative error?

(a) 3%

(b) 2.5%

(c) 2.43%

(d) 3.43%

This question was posed to me at a job interview.

My doubt is from Errors in Data and Calculations topic in portion Presentation and Analysis of Data of Bioprocess Engineering

Answer 1

Right answer is (c) 2.43%

To explain: Given:

True value = 123cms

Measured value = 120cms

Firstly, let us find out the absolute error.

We know by subtracting true value with measured value we get absolute error = 123 – 120 = 3cms

Therefore, absolute error = 3cms

Now, let us find out the relative error = absolute error/True value x 100

= 3/123 x 100 = 2.43%

Therefore, the relative error for the given values = 2.43%.