The presence of diversity at the junction of territories of two different habitats is known as

Two electric charges of $9 \mu C$ and $-3 \mu C$ are placed $0.16 \ m$ apart in air. There will be a point $P$ on the line joining the two charges and in between them where the electric potential is zero. The distance of $P$ from the $9 \mu C$ charge is (in $m$)

If the line $2x - 3y + 5 = 0$ is the perpendicular bisector of the line segment joining $(1, -2)$ and $(\alpha, \beta)$,then $\alpha + \beta =$

If $a$ and $b$ are positive integers such that $b > a$,then $\lim _{n \rightarrow \infty} \left[ \frac{1}{na} + \frac{1}{na+1} + \frac{1}{na+2} + \ldots + \frac{1}{nb} \right] = $

The product of the lengths of the perpendiculars from any point on the hyperbola $x^2 - y^2 = 8$ to its asymptotes is:

Bell metal is an alloy of which of the following?