The refractive index of the ionosphere is ........

The sun delivers $10^{3} \,W m^{-2}$ of electromagnetic flux on the Earth's surface. The total power that is incident on a roof of dimensions $6 \,m \times 30 \,m$ is . . . . . . .

If the magnetic field in a plane electromagnetic wave is given by $\overrightarrow{B} = 3 \times 10^{-8} \sin (1.6 \times 10^{3} x + 48 \times 10^{10} t) \hat{j} \; T$,then what will be the expression for the electric field?

An electromagnetic wave travels along the $z$-axis. Which of the following pairs of space and time-varying fields would generate such a wave?

The magnetic field of a plane electromagnetic wave is $\overrightarrow{B} = 3 \times 10^{-8} \sin [200 \pi(y + ct)] \hat{i} \, T$,where $c = 3 \times 10^{8} \, m/s$ is the speed of light. The corresponding electric field is:

An electron is constrained to move along the $y$-axis with a speed of $0.1 c$ ($c$ is the speed of light) in the presence of an electromagnetic wave,whose electric field is $\overrightarrow{E} = 30 \hat{j} \sin(1.5 \times 10^7 t - 5 \times 10^{-2} x) \, V/m$. The maximum magnetic force experienced by the electron will be: (given $c = 3 \times 10^8 \, m/s$ and electron charge $q = 1.6 \times 10^{-19} \, C$)