If a unit vector is represented by $0.5\hat{i} - 0.8\hat{j} + c\hat{k}$,then the value of $c$ is:

Which of the following is $NOT$ a characteristic of Phylum $Annelida$?

When a charge of $3\, C$ is placed in a uniform electric field,it experiences a force of $3000\, N$. Within this field,the potential difference between two points separated by a distance of $1\, cm$ is:

If $\sin^{-1}(\frac{x}{5}) + \csc^{-1}(\frac{5}{4}) = \frac{\pi}{2}$,then $x = $

If the normal to the curve $y^2 = 5x - 1$ at the point $(1, -2)$ is of the form $ax - 5y + b = 0$,then $a$ and $b$ are:

The $INCORRECT$ statement about the dissolution of an alkali metal in liquid ammonia is