Four persons measure the length of a rod as $20.00 \ cm$, $19.75 \ cm$, $17.01 \ cm$, and $18.25 \ cm$. The relative error in the measurement of the average length of the rod is:

Two resistors of resistances $R_1 = (300 \pm 3) \,\Omega$ and $R_2 = (500 \pm 4) \,\Omega$ are connected in series. The equivalent resistance of the series combination is

Explain the effect of multiplication or division of errors on the final result.

$A$ physical quantity $x$ is related as $x = \frac{\sqrt{a}b^3}{c^4d^{-4}}$. Relative errors in the quantities $a, b, c$ and $d$ are $2\%, 1\%, 3\%$ and $4\%$ respectively. The relative error in $x$ will be: (in $\%$)

$A$ set of defective observation weights is used by a student to find the mass of an object using a physical balance. $A$ large number of readings will reduce:

$A$ force $F$ is applied on a square area of side $L$. If the percentage error in the measurement of $L$ is $2 \%$ and that in $F$ is $4 \%$,what is the maximum percentage error in pressure (in $\%$)?