$A$ student measures the time period of $100$ oscillations of a simple pendulum four times. The data set is $90\;s$,$91\;s$,$95\;s$,and $92\;s$. If the minimum division in the measuring clock is $1\;s$,then the reported mean time should be

What is error in measurement? What is mistake in measurement?

$A$ balance is made using a uniform metre scale of mass $100 \ g$ and two plates each of mass $200 \ g$ fixed at the two ends of the scale. The balance is pivoted at the $45 \ cm$ mark. If a $300 \ g$ weight is placed in the plate at $0 \ cm$ to weigh vegetables placed in the plate at $100 \ cm$,what is the error in the measurement (in $g$)?

$A$ physical quantity $x$ is calculated from the relation $x = \frac{a^2 b^3}{c \sqrt{d}}$. If the percentage errors in $a, b, c,$ and $d$ are $2\%, 1\%, 3\%,$ and $4\%$ respectively,what is the percentage error in $x$?

The period of oscillation of a simple pendulum is $T = 2 \pi \sqrt{\frac{L}{g}}$. The measured value of $L$ is $1.0 \text{ m}$ using a meter scale with a minimum division of $1 \text{ mm}$,and the time for one complete oscillation is $1.95 \text{ s}$ measured using a stopwatch with a resolution of $0.01 \text{ s}$. The percentage error in the determination of $g$ will be ..... $\%$.

The period of oscillation of a simple pendulum in an experiment is recorded as $2.63\, s, 2.56\, s, 2.42\, s, 2.71\, s$,and $2.80\, s$ respectively. The average absolute error is ......... $s$.