The radius $(r)$,length $(l)$,and resistance $(R)$ of a metal wire were measured in the laboratory as:
$r = (0.35 \pm 0.05) \text{ cm}$
$R = (100 \pm 10) \text{ } \Omega$
$l = (15 \pm 0.2) \text{ cm}$
The percentage error in the resistivity of the material of the wire is: (in $\%$)

$A$ physical quantity $A$ can be determined by measuring parameters $B, C, D$ and $E$ using the relation $A = \frac{B^\alpha C^\beta}{D^\gamma E^\delta}$. If the maximum percentage errors in the measurement of $B, C, D$ and $E$ are $b\%, c\%, d\%$ and $e\%$ respectively,then the maximum percentage error in the value of $A$ is:

Explain the error of a sum or a difference.

The formula for the physical quantity is $P = \frac{x^3 y}{z^2}$ and the percentage error in the determination of physical quantities $x, y, z$ are $0.6 \%$,$3 \%$,and $1.3 \%$ respectively. The percentage error in the measurement of $P$ is (in $\%$)

Two resistances are given as $R_1 = (10 \pm 0.5) \ \Omega$ and $R_2 = (15 \pm 0.5) \ \Omega$. The percentage error in the measurement of equivalent resistance when they are connected in parallel is (in $\%$)

To find the spring constant $(k)$ of a spring experimentally,a student commits $2 \%$ positive error in the measurement of time and $1 \%$ negative error in the measurement of mass. The percentage error in determining the value of $k$ is (in $\%$)