The $rms$ value of the electric field of the light coming from the sun is $720 \ N \ C^{-1}$. The average energy density of the electromagnetic wave is $...... \ J \ m^{-3}$.

The electric field in a plane electromagnetic wave is given by $\overrightarrow{E} = 200 \cos \left[ (0.5 \times 10^{3} \text{ m}^{-1}) x - (1.5 \times 10^{11} \text{ rad/s}) t \right] \hat{j} \text{ V/m}$. If this wave falls normally on a perfectly reflecting surface having an area of $100 \text{ cm}^{2}$,and the radiation pressure exerted by the electromagnetic wave on the surface is $\frac{x}{10^{9}} \text{ N/m}^{2}$,find the value of $x$.

About $20 \%$ of the power of a $100 \ W$ bulb is converted to visible radiation. Assuming that the radiation is emitted isotropically and neglecting reflection,the average intensity of visible radiation at a distance of $5 \ m$ is $\frac{\alpha}{25 \pi} \ W/m^2$. The value of $\alpha$ is

Which one of the following statements is not the property of light?

In a plane electromagnetic wave,the directions of the electric field and magnetic field are represented by $\hat{k}$ and $2\hat{i}-2\hat{j}$,respectively. What is the unit vector along the direction of propagation of the wave?

Radio waves and visible light in vacuum have