Average force exerted on a non-reflecting surface at normal incidence is $$2.4 \times 10^{-4} \mathrm{~N}$$. If $$360 \mathrm{~W} / \mathrm{cm}^2$$ is the light energy flux during span of 1 hour 30 minutes, Then the area of the surface is:
In the given electromagnetic wave $$\mathrm{E}_{\mathrm{y}}=600 \sin (\omega t-\mathrm{kx}) \mathrm{Vm}^{-1}$$, intensity of the associated light beam is (in $$\mathrm{W} / \mathrm{m}^2$$ : (Given $$\epsilon_0=9 \times 10^{-12} \mathrm{C}^2 \mathrm{~N}^{-1} \mathrm{~m}^{-2}$$ )
Electromagnetic waves travel in a medium with speed of $$1.5 \times 10^8 \mathrm{~m} \mathrm{~s}^{-1}$$. The relative permeability of the medium is 2.0. The relative permittivity will be:
Match List I with List II :
LIST I EM-Wave |
LIST II Wavelength Range |
||
---|---|---|---|
A. | Infra-red | I. | $$<10^{-3}$$ nm |
B. | Ultraviolet | II. | 400 nm to 1 nm |
C. | X-rays | III. | 1 mm to 700 nm |
D. | Gamma rays | IV. | 1 nm to $$10^{-3}$$ nm |
Choose the correct answer from the options given below :