1
JEE Main 2019 (Online) 9th January Morning Slot
+4
-1
A mixture of 2 moles of helium gas (atomic mass = 4 u), and 1 mole of argon gas (atomic mass = 40 u) is kept at 300 K in a container. The ratio of their rms speeds $$\left[ {{{{V_{rms}}\,(helium)} \over {{V_{rms}}\,(\arg on)}}} \right],$$ is close to :
A
3.16
B
0.32
C
0.45
D
2.24
2
JEE Main 2019 (Online) 9th January Morning Slot
+4
-1
Temperature difference of 120oC is maintained between ends of a uniform rod AB of length 2L. Another bent rod PQ, of same cross-section as AB and length $${{3L} \over 2},$$ is connected across AB (see figure). In steady state, temperature difference between P and Q will be close to :

A
45oC
B
75oC
C
60oC
D
35oC
3
JEE Main 2019 (Online) 9th January Morning Slot
+4
-1
A gas can be taken from A to B via two different processes ACB and ADB.

When path ACB is used 60 J of heat flows into the system and 30 J of work is done by the system. If path ADB is used work done by the system is 10 J. The heat Flow into the system in path ADB is :
A
40 J
B
80 J
C
100 J
D
20 J
4
JEE Main 2019 (Online) 9th January Morning Slot
+4
-1
A rod, of length L at room temperature and uniform area of cross section A, is made of a metal having coefficient of linear expansion $$\alpha$$/oC. It is observed that an external compressive force F, is applied on each of its ends, prevents any change in the length of the rod, when its temperature rises by $$\Delta$$TK. Young's modulus, Y, for this metal is :
A
$${F \over {A\alpha \Delta T}}$$
B
$${F \over {A\alpha (\Delta T - 273)}}$$
C
$${F \over {2A\alpha \Delta T}}$$
D
$${{2F} \over {A\alpha \Delta T}}$$
EXAM MAP
Medical
NEET