Abjt differential amplifier, biased to have re = 50  and utilizing two 50- emitter resistors and 5-k loads, drives a second differential stage biased to have re = 50 . all bjts have β = 100. what is the voltage gain of the first stage? also find the input resistance of the first stage, and the current gain from the input of the first stage to the collectors of the second stage

An air-conditioning system consists of a heating section and an evaporative cooler. air enters the heating section at 10°c and 70 percent relative humidity at a rate of 30m^3/min, and it leaves the evaporative cooler at 20°c and 60 percent relatively humidity. if the air conditioning system operates at a total pressure of 98 kpa, determine (a) the temperature and relative humidity of the air when it leaves the heating section, (b) the rate of heat transfer in the heating section, and (c) the rate of water added to air in the evaporative cooler