If the length of a cylinder is $l=(4.00 \pm 0.01) cm$, radius $r =(0.250 \pm 0.001) \;cm$ and mass $m =6.25 \pm 0.01\; g$. Calculate the percentage error in determination of density.
$12.1$
$0.121$
$12.18 $
$1.21$
The least count of a stop watch is $0.2\, second$. The time of $20\, oscillations$ of a pendulum is measured to be $25\, second$. The percentage error in the measurement of time will be ........ $\%$
The density of a solid metal sphere is determined by measuring its mass and its diameter. The maximum error in the density of the sphere is $\left(\frac{x}{100}\right) \% .$ If the relative errors in measuring the mass and the diameter are $6.0 \%$ and $1.5 \%$ respectively, the value of $x$ is
$Assertion$: In the measurement of physical quantities direct and indirect methods are used.
$Reason$ : The accuracy and precision of measuring instruments along with errors in measurements should be taken into account, while expressing the result.
Write a note on combination of error.
In the determination of Young's modulus $\left(Y=\frac{4 MLg }{\pi / d ^2}\right)$ by using Searle's method, a wire of length $L=2 \ m$ and diameter $d =0.5 \ mm$ is used. For a load $M =2.5 \ kg$, an extension $\ell=0.25 \ mm$ in the length of the wire is observed. Quantities $d$ and $\ell$ are measured using a screw gauge and a micrometer, respectively. They have the same pitch of $0.5 \ mm$. The number of divisions on their circular scale is $100$ . The contributions to the maximum probable error of the $Y$ measurement