In a triangle $A B C$, with usual notations, if $\frac{b+c}{11}=\frac{c+a}{12}=\frac{a+b}{13}$ Then $\cos \mathrm{A}: \cos \mathrm{B}: \cos \mathrm{C}$ is

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

Let ' $W$ ' joule be the work done to move an electric charge ' $q$ ' coulomb from a place $A$, where potential is -5 volt to another place $B$ where potential is ' $V$ ' volt. The value of ' $V$ ' is

A stone of mass 1 kg tied to a light inextensible string of length $L=\frac{5}{3} m$ is rotating in a circular path of radius $L$ in a vertical plane. If the ratio of maximum tension in the string to the minimum tension in the string is 3 , the speed of the stone at the highest point of the circle is ( $\mathrm{g}=$ acceleration due to gravity)