Let $O$ be the origin and $A$ be a point on the curve $y^2=4x$. Then the locus of the midpoint of $OA$ is:

The voltage of an $ac$ source varies with time according to the equation $V = 100 \sin(100 \pi t) \cos(100 \pi t)$,where $t$ is in $seconds$ and $V$ is in $volts$. Then:

Which zone of the blast furnace has the highest temperature?

The reading of the ammeter in the circuit shown will be: (in $A$)

When the size of a spherical nanoparticle decreases from $30 \, nm$ to $10 \, nm$,the ratio of surface area to volume becomes:

The filiform apparatus is a characteristic feature of which of the following?