A0.5 mhz antenna carried by an airplane flying in air over the ocean generates a plane wave that is normally incident upon the air-water interface. the amplitude of the incident electromagnetic wave is 3 (kv/m). the airplane is trying to communicate with a submarine which is submerged below the ocean surface. the submarine's receiver requires a minimum signal amplitude of 0.01 (mu v/m). ocean water has the following material properties epsilon _r = 81 mu _r =1 sigma = 5 s/m from this information, what is the maximum depth d of the submarine for which successful communication is possible?

Amass of m 1.5 kg of steam is contained in a closed rigid container. initially the pressure and temperature of the steam are: p 1.5 mpa and t 240°c (superheated state), respectively. then the temperature drops to t2= 100°c as the result of heat transfer to the surroundings. determine: a) quality of the steam at the end of the process, b) heat transfer with the surroundings. for: p1.5 mpa and t 240°c: enthalpy of superheated vapour is 2900 kj/kg, specific volume of superheated vapour is 0. 1483 m/kg, while for t 100°c: enthalpy of saturated liquid water is 419kj/kg, specific volume of saturated liquid water is 0.001043m/kg, enthalpy of saturated vapour is 2676 kj/kg, specific volume of saturated vapour is 1.672 m/kg and pressure is 0.1 mpa.

Thermal stresses are developed in a metal when its a) initial temperature is changed b) final temperature is changed c) density is changed d) thermal deformation is prevented e) expansion is prevented f) contraction is prevented

Inadequate stores control is not an obstacle to effective work order system. (clo4) a)-true b)-false