The magnetic susceptibility of a paramagnetic material at $-73\,^{\circ}C$ is $0.0075$. What will be its value at $-173\,^{\circ}C$?

What is the biological concentration of $DDT$ in the body fat of Indian people?

If the pair of lines $ax^2-7xy-3y^2=0$ and $2x^2+xy-6y^2=0$ have exactly one line in common and $a$ is an integer,then the equation of the pair of bisectors of the angles between the lines $ax^2-7xy-3y^2=0$ is

Which of the following species has no $p\pi-p\pi$ bond but has a bond order equal to $O_2$?

$A$ tension of $22 ~N$ is applied to a copper wire of cross-sectional area $0.02 ~cm^2$. The Young's modulus of copper is $1.1 \times 10^{11} ~N/m^2$ and the Poisson's ratio is $0.32$. The decrease in cross-sectional area will be:

The weight in grams of a non-volatile solute (mol. wt. $60$) to be dissolved in $90 \ g$ of water to produce a relative lowering of vapour pressure of $0.02$ is