Which one of the following is a stimulant?

Five capacitors,each of capacitance $C$,are connected as shown in the figure. The ratio of the equivalent capacitance between $P$ and $R$ to the equivalent capacitance between $P$ and $Q$ is:

Which of the following pairs of organs consists only of endocrine glands?

What is the product formed when phenol reacts with concentrated $HNO_3$?

If the polar of a point on the circle $x^2+y^2=p^2$ with respect to the circle $x^2+y^2=q^2$ touches the circle $x^2+y^2=r^2$,then $p, q, r$ are in

In order to calculate the map distance of genes on a chromosome,one must know the