If $x = 10.0 \pm 0.1$ and $y = 10.0 \pm 0.1$,then $2x - 2y$ is equal to

In an experiment for the measurement of $g$ using a simple pendulum,the time period was measured with an accuracy of $0.2 \%$ while the length was measured with an accuracy of $0.5 \%$. The percentage accuracy in the value of $g$ thus obtained is: (in $\%$)

Explain least count and least count error. Write a note on least count error.

The temperature of a body measured by a thermometer with a least count of $0.2 ^\circ C$ is $37.8 ^\circ C$. The temperature with error is represented as ... and the percentage error of the observation is ...

The values of a number of quantities are used in a mathematical formula. The quantity that should be most precise and accurate in measurement is the one

$A$ student measures time for $20$ oscillations of a simple pendulum as $30 \ s, 32 \ s, 35 \ s$ and $35 \ s$. If the minimum division in the measuring clock is $1 \ s$,then the correct mean time (in seconds) is: