The electric field of a plane electromagnetic wave is

$$E = {a_x}{C_{1x}}\cos (\omega t - \beta z) + {a_y}{C_{1y}}\cos (\omega t - \beta z + \theta )$$ V/m.

Which of the following combination(s) will give rise to a left handed elliptically polarized (LHEP) wave?

A transparent dielectric coating is applied to glass ($$\varepsilon _r=4,\mu_r=1$$) to eliminate the reflection of red light ($$\lambda_0=0.75~\mu\mathrm{m}$$). The minimum thickness of the dielectric coating, in $$\mu\mathrm{m}$$, that can be used is __________ (rounded off to two decimal places).

The vector function $F(r) = -x \hat{i} + y \hat{j}$ is defined over a circular arc C shown in the figure,

The line integral of $\int\limits_{C} \mathbf{F(r)} \cdot d\mathbf{r}$ is