1
JEE Main 2020 (Online) 8th January Morning Slot
+4
-1
The plot that depicts the behavior of the mean free time t (time between two successive collisions) for the molecules of an ideal gas, as a function of temperature (T), qualitatively, is:
(Graphs are schematic and not drawn to scale)
A
B
C
D
2
JEE Main 2020 (Online) 8th January Morning Slot
+4
-1
A thermodynamic cycle xyzx is shown on a V-T diagram. The P-V diagram that best describes this cycle is :
(Diagrams are schematic and not to scale)
A
B
C
D
3
JEE Main 2020 (Online) 7th January Evening Slot
+4
-1
Out of Syllabus
Two ideal Carnot engines operate in cascade (all heat given up by one engine is used by the other engine to produce work) between temperature, T1 and T2 . The temperature of the hot reservoir of the first engine is T1 and the temperature of the cold reservoir of the second engine is T2 . T is temperature of the sink of first engine which is also the source for the second which is also the source for the second engine. How is T related to T1 and T2 . If both engines perform equal amount of work?
A
$$T = {{2{T_1}{T_2}} \over {{T_1} + {T_2}}}$$
B
$$T = \sqrt {{T_1}{T_2}}$$
C
$$T = {{{T_1} + {T_2}} \over 2}$$
D
T = 0
4
JEE Main 2020 (Online) 7th January Evening Slot
+4
-1
Under an adiabatic process, the volume of an ideal gas gets doubled. Consequently the mean collision time between the gas molecule changes from $${\tau _1}$$ to $${\tau _2}$$ . If $${{{C_p}} \over {{C_v}}} = \gamma$$ for this gas then a good estimate for $${{{\tau _2}} \over {{\tau _1}}}$$ is given by :
A
$${\left( 2 \right)^{{{1 + \gamma } \over 2}}}$$
B
2
C
$${\left( {{1 \over 2}} \right)^{{{1 + \gamma } \over 2}}}$$
D
$${\left( {{1 \over 2}} \right)^\gamma }$$
EXAM MAP
Medical
NEET