Helium gas is to be heated steadily by a 3-kW electric resistance heater as it flows through an insulated duct. If the helium enters at 50°C at a rate of 0.08 kg/s, the exit temperature of helium will be

Question

Quizplus · Accepted Answer

Solved by EES Software. Solutions can be verified by copying-and-pasting the following lines on a blank EES screen. 
Cp=5.1926 "kJ/kg-C"
T1=50 "C"
 m_dot=0.08 "kg/s"
W_dot_e=3 "kJ/s"
W_dot_e=m_dot*Cp*(T2-T1)
 
"Some Wrong Solutions with Common Mistakes:"
Cv=3.1156 "kJ/kg.K"
W_dot_e=Cp*(W1_T2-T1) "Not using mass flow rate"
W_dot_e=m_dot*Cv*(W2_T2-T1) "Using Cv"
W_dot_e=m_dot*Cp*W3_T2 "Ignoring T1"

Helium Gas Is to Be Heated Steadily by a 3-KW