Consider free space path loss in your wireless communication systems: 4. Where Pt signal power at transmitting antenna Pr signal power at receiving antenna · λ=carrier signal wavelength .d communication distance between antennas Usually there is a minimum requirement of Signal to Noise Ratio SNR related to Pr. Please nominate at least two strategies in your communication system in order to increase the communication distance d. Explain why?

Consider a large isothermal enclosure that is maintained at a uniform temperature of 2000 k. calculate the emissive power of the radiation that emerges from a small aperture on the enclosure surface. what is the wavelength ? , below which 10% of the emission is concentrated? what is the wavelength ? 2 above which 10% of the emission is concentrated? determine the wavelength at which maximum spectral emissive power occurs. what is the irradiation incident on a small object placed inside the enclosure?

Modern high speed trains do not have perpendicular expansion gaps where rails are joined end-to-end any more they are mostly welded together but what might happen if there was a spell of particularly hot weather that causes inspection of the tracks?

Prove the equivalence between the two statements of the 2nd law of thermodynamics (i.e., a violation of one statement leads to the violatio the other statement)