Choose the correct statement.

The typical wavelength of X-ray is

At an instant, a plane electromagnetic wave has its magnetic field in the direction of the vector $\hat{\mathbf{i}}-\hat{\mathbf{j}}$ and its electric field is in the direction of $\hat{\mathbf{i}}+\hat{\mathbf{j}}$. The wave is travelling along which direction?

A parallel-plate capacitor with circular plates is being discharged. The radius of the circular plate is 10 cm . A circular loop of radius 20 cm is concentric with the capacitor and located halfway between the plates. If the electric field between the plates is charging at the rate $3.6 \times 10^{12} \mathrm{~V} /(\mathrm{ms})$, then the displacement current through the loop is

$$ \text { (Assume } \frac{1}{4 \pi \varepsilon_0}=9 \times 10^9 \mathrm{Nm}^2 / \mathrm{C}^2 \text { ) } $$