question_answer 13)

A physical quantity P is related to four observations: a, b, c and d as follows : The percentage errors of measurement in a, b, c and d are 1%, 3%, 4% and 2% respectively. What is the percentage error in the quantity P Rs If the value of P calculated using the above relation turns out to be 3.763 , to what value should you round off the result ?                 

Answer:

Given:   The percentage error in the quantity P is given by   . Since 13% = 0.13, so there are two significant figures in the percentage error. Hence P should also be rounded off to 2 significant figures.                             P = 3.763 = 3.8.