Epsom salt is a hydrate of which of the following?

Nicotine acts as a stimulant because it mimics the effect of

The equation of the parabola with the focus $(3,0)$ and the directrix $x+3=0$ is:

Two coherent sources of intensity ratio $x^2$ interfere. In the interference pattern,which of the following relations is correct?

An ideal transformer has $500$ and $5000$ turns in primary and secondary windings respectively. If the primary voltage is connected to a $6\,V$ battery, then the secondary voltage is.......$V$.

The number of circles that touch all the straight lines $x+y=4$,$x-y=-2$,and $y=2$ is