The number of ways that $8$ beads of different colours can be strung as a necklace is

Which one has the maximum oxidation number of phosphorus?

In the circuit shown in the figure,the $AC$ source gives a voltage $V = 20 \cos(2000t)$. Neglecting source resistance,the voltmeter and ammeter readings will be

Which one of the following salts gives an acidic solution in water?

The set $\{x \in R: \cos 2x + 2 \cos^2 x = 2\}$ is equal to

Two sides of a triangle are given by the roots of the equation $x^2-5x+6=0$ and the angle between the sides is $\frac{\pi}{3}$. Then,the perimeter of the triangle is