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

The best method to reduce random error is

The length of a cylinder is measured with a meter rod having a least count of $0.1 \text{ cm}$. Its diameter is measured with vernier calipers having a least count of $0.01 \text{ cm}$. The length of the cylinder is $8.0 \text{ cm}$ and the radius is $4.0 \text{ cm}$. Find the percentage error in the calculated value of the volume. (in $\%$)

$A$ 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 $g$)?

For $z = a^{2} x^{3} y^{1/2}$,where $a$ is a constant. If the percentage error in the measurement of $x$ and $y$ are $4\%$ and $12\%$,respectively,then the percentage error for $z$ will be $........... \%$.

$A$ physical quantity $Q$ is found to depend on observables $x, y$ and $z$,obeying the relation $Q = \frac{x^3 y^2}{z}$. The percentage errors in the measurements of $x, y$ and $z$ are $1\%, 2\%$ and $4\%$ respectively. What is the percentage error in the quantity $Q$ (in $\%$)?