Thermodynamic Processes

Question 1

Isothermal

Answer 1

•T= constant 
•/\U=0 (internal energy constant)
•PV=constant
•W= nRTlog(Vf/Vi) = nRTlog(Pf/Pi)
•B=P
•P-V curve is a Rectangular Hyperbola
Molar heat capacity(Cv) =infinity

Question 2

Isochoric

Answer 2

• V=constant
• /\W=0
• /\U=/\Q
• P/T=constant
• P-V curve is a straight line parallel to Y-axis
• molar heat capacity =Cv

Question 3

Isobaric

Answer 3

• P = constant
• molar heat capacity = Cp
• /\U=nCv/\T
• W =nR/\T = P/\V
• P-V curve is a straight line parallel to X-axis

Question 4

Adiabatic

Answer 4

• /\Q=0
• /\U =-/\W
• molar heat capacity(C) =0
• On expanding system cools
• On contracting system heats up
• PV^y = constant
• TV^(y-1) = constant
• P^(1-y)T^y = constant
• W = (nR/\T)/(y-1) = (P1V1 - P2V2)/(y-1)
• y= adiabatic slope/isothermal slope

Question 5

Cyclic

Answer 5

•for a complete cycle
/\U=0
•Net heat = heat supplied + heat rejected
• Efficiency (n) = work done/heat supplied X 100

Question 6

In adiabatic compression the decrease in volume is associated with

Answer 6

Increase in temperature and pressure

Question 7

Heat energy is independent of the

Answer 7

State of the system

Question 8

Thermal resistance

Answer 8

Rthermal = l/KA

Question 9

When Slabs are connected in series the equivalent thermal conductivity constant =

Answer 9

Keq = (l1 + l2)/ (l1/K1 + l2/K2)

Question 10

When Slabs are connected in parallel the equivalent thermal conductivity constant =

Answer 10

Keq = (K1A1 + K2A2)/(A1 + A2)