What is the fractional error in $g$ calculated from $T = 2\pi \sqrt {l/g}$? Given fractional errors in $T$ and $l$ are $\pm x$ and $\pm y$ respectively?

Explain the error of a sum or a difference.

The radius of a sphere is $(5.3 \pm 0.1) \, cm$. The percentage error in its volume is

The time period of a simple harmonic oscillator is $T = 2 \pi \sqrt{\frac{m}{k}}$. The measured value of mass $(m)$ of the object is $10 \ g$ with an accuracy of $10 \ mg$, and the time for $50$ oscillations of the spring is found to be $60 \ s$ using a watch of $2 \ s$ resolution. The percentage error in the determination of the spring constant $(k)$ is . . . . . . %.

If two resistors have resistances $R_1 = (350 \pm 3) \text{ } \Omega$ and $R_2 = (140 \pm 4) \text{ } \Omega$, then the percentage error for the sum and difference of $R_1$ and $R_2$ are respectively:

$A$ wire has a mass $0.3 \pm 0.003 \text{ g}$,radius $0.5 \pm 0.005 \text{ mm}$ and length $6 \pm 0.06 \text{ cm}$. The maximum percentage error in the measurement of its density is (in $\%$)