$DDT$ residues are rapidly passed through food chains causing biomagnification. What is the reason for this?

If $\bar{M}_w$ is the weight average molecular weight and $\bar{M}_n$ is the number average molecular weight of a polymer,the poly dispersity index $(PDI)$ of the polymer is given by

If the combined equation of the lines joining the origin to the points of intersection of the curve $x^2+y^2-2x-4y+2=0$ and the line $x+y-2=0$ is $(l_1x+m_1y)(l_2x+m_2y)=0$,then $l_1+l_2+m_1+m_2=$

Three masses $700\,g, 500\,g$ and $400\,g$ are suspended at the end of a spring as shown and are in equilibrium. When the $700\,g$ mass is removed,the system oscillates with a period of $3\,s$. When the $500\,g$ mass is also removed,it will oscillate with a period of .... $s$.

The equation of a straight line,perpendicular to $3x - 4y = 6$ and forming a triangle of area $6$ sq. units with the coordinate axes,is

Let $A = \{ (x, y) : y = e^x, x \in R \} $ and $B = \{ (x, y) : y = e^{-x}, x \in R \} $. Then