Let $z = a - \frac{i}{2}$,where $a \in R$. Then $|i + z|^2 - |i - z|^2$ is equal to

If $z = \sec(y - ax) + \tan(y + ax)$,then $\frac{\partial^2 z}{\partial x^2} - a^2 \frac{\partial^2 z}{\partial y^2}$ is equal to

In the $CGS$ system,the magnitude of the force is $100 \text{ dynes}$. In another system where the fundamental physical quantities are kilogram,meter,and minute,the magnitude of the force is:

Identify phenacetin from the following.

The degree of ionization of $0.10 \ M$ lactic acid is $4.0 \ \%$. The value of $K_a$ is

$A$ wire fixed at the upper end stretches by length $l$ by applying a force $F$. The work done in stretching is