According to Joule's law of heating,heat produced $H = I^2Rt$,where $I$ is current,$R$ is resistance,and $t$ is time. If the errors in the measurement of $I, R$,and $t$ are $3\%, 4\%$,and $6\%$ respectively,then the error in the measurement of $H$ is:

In a simple pendulum experiment for determination of acceleration due to gravity $(g)$, time taken for $20$ oscillations is measured by using a watch of $1\,s$ least count. The mean value of time taken comes out to be $30\,s$. The length of the pendulum is measured by using a meter scale of least count $1\,mm$ and the value obtained is $55.0\,cm$. The percentage error in the determination of $g$ is close to ........... $\%$

$A$ 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:

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 least count of a stopwatch is $\frac{1}{5} \ s$. The time for $20$ oscillations of a pendulum is measured to be $25 \ s$. The percentage error in the measurement of time will be .......... $\%$

If $\theta_1 = 25.5 \pm 0.1 \, ^\circ C$ and $\theta_2 = 35.3 \pm 0.1 \, ^\circ C$,find $\theta_1 - \theta_2$.