Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): In Vernier calliper if positive zero error exists, then while taking measurements, the reading taken will be more than the actual reading.
Reason (R): The zero error in Vernier Calliper might have happened due to manufacturing defect or due to rough handling.
In the light of the above statements, choose the correct answer from the options given below:
Answer: (B) Both (A) and (R) are correct but (R) is not the correct explanation of (A)
With a positive zero error, the vernier zero lies to the right of the main scale zero when the jaws are closed, so every observed reading exceeds the true value by that error. (A) is correct.
Zero error can arise from manufacturing defects or rough handling, so (R) is also correct. But (R) only gives the cause of zero error; it does not explain why a positive zero error makes readings larger. So (R) is not the correct explanation.
Solution by Sreeraj P, M.Sc Physics