What is the magnetosphere?
a. a stream of electrically charged particles flowing at high speeds from the sun
b. the region of earth's magnetic field shaped by the solar wind
c. a glowing region in the atmosphere caused by charged particles from the sun
d. the angle between geographic north and the magnetic pole in the northern hemisphere

Air enters a gas turbine with two stages of compression and two stages of expansion at 100 kpa and 17°c. this system uses a regenerator as well as reheating and intercooling – the intercooler returns the air to the inlet temperature. the pressure ratio across each compressor is 4 ; 300 kj/kg of heat are added to the air in each combustion chamber; and the regenerator operates perfectly while increasing the temperature of the cold air by 20°c. determine the system’s thermal efficiency. assume isentropic operations for all compressor and the turbine stages and use constant specific heats at room temperature. (0.378)