The variation of magnetic susceptibility $(\chi )$ with temperature for a diamagnetic substance is best represented by

$\int \frac{dx}{a^2 \sin^2 x + b^2 \cos^2 x}$ is equal to

The depletion layer in the $p-n$ junction is caused by

Which of the following is a Lewis base?

If the foot of the perpendicular from $(0,0,0)$ to a plane is $(1,2,3)$,then the equation of the plane is

Let $S=\{x \in(-\pi, \pi): x \neq 0, \pm \frac{\pi}{2}\}$. The sum of all distinct solutions of the equation $\sqrt{3} \sec x+\operatorname{cosec} x+2(\tan x-\cot x)=0$ in the set $S$ is equal to