Find the value of $V_{AB}$ in the given circuit.

One of the endangered species of Indian medicinal plants is

$I$ carried $1000\,kg$ of watermelon in summer by train. In the beginning,the water content was $99\%$. By the time $I$ reached the destination,the water content had dropped to $98\%$. The reduction in the weight of the watermelon was $.......\,kg$.

The set of solutions of the system of equations
$
\begin{aligned}
x+y & =\frac{2 \pi}{3} \\
\text{and} \quad \cos x+\cos y & =\frac{3}{2},
\end{aligned}
$
where $x, y$ are real,is

If $u=f(r)$,where $r^2=x^2+y^2$,then $\left(\frac{\partial^2 u}{\partial x^2}+\frac{\partial^2 u}{\partial y^2}\right)$ is equal to

Which of the following statements is incorrect regarding $DDT$?