A 41-m length of wire is stretched horizontally between two vertical posts. The wire carries a current of 82 A and experiences a magnetic force of 0.13 N. Find the magnitude of the earth's magnetic field at the location of the wire, assuming the field makes an angle of 61.0° with respect to the wire.

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)