Which of the following is used as an antibiotic?

Suppose there is a hole in a copper plate. On heating the plate,the diameter of the hole would:

$A$ coil of radius '$r$' is placed on another coil (whose radius is '$R$' and current through it is changing) so that their centers coincide. $(R \gg r)$. If both are coplanar,then the mutual inductance between them is proportional to

The curve $f(x) = e^x \sin x$ is defined in the interval $[0, 2\pi]$. The value of $x$ for which the slope of the tangent drawn to the curve at $x$ is maximum,is

Which of the following taxonomic categories of the housefly is incorrectly matched?

Let $A(3-i)$ and $B(2+i)$ be two points in the Argand plane. If the point $P$ represents the complex number $z=x+iy$,which satisfies $|z-3+i|=|z-2-i|$,then the locus of the point $P$ is