A precise measurement guarantees accuracy of the measured quantity.

A metal strain gauge has gauge factor of two, it's nominal resistance is $$120$$ Ohms. It is undergoes a strain of $${10^{ - 5}},$$ the value of change of resistance in response to the strain is

A resistance is measured by the voltmeter- ammeter method employing d.c. excitation and a voltmeter of very high resistance connected directly across the unknown resistance. If the voltmeter and ammeter readings are subject to maximum possible errors of $$ \pm 2.4\% $$ and $$ \pm 1.0\% $$ respectively, then the magnitude of the maximum possible percentage error in the value of resistance deduced from the measurement is nearly