For an ideal gas, AB and CD are two isothermals at temperatures T
1 and T
2(
T1>T2), respectively. AD and BC represent two adiabatic paths as shown in figure. Let V
A, V
B, V
C and V
D be the volumes of the gas at A, B, C and D respectively. If
VBVc=2, then
VAVD=______.
