### JEE Mains Previous Years Questions with Solutions

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1

### AIEEE 2004

As the temperature is raised from 20°C to 40°C, the average kinetic energy of neon atoms changes by a factor of which of the following?
A
1/2
B
2
C
$313\over293$
D
$\sqrt{313\over293}$

## Explanation

${{K.E\,\,of\,\,neon\,\,at\,\,{{40}^ \circ }C} \over {K.E\,\,of\,\,neon\,\,at\,\,{{20}^ \circ }C}}$

$= {{{3 \over 2}K \times 313} \over {{3 \over 2}K \times 293}}$

$= {{313} \over {293}}$
2

### AIEEE 2003

According to the kinetic theory of gases, in an ideal gas, between two successive collisions of a gas molecule travels
A
in a wavy path
B
in a straight line path
C
with an accelerated velocity
D
in a circular path

## Explanation

According to kinetic theory the gas molecules are in a state of constant rapid motion in all possible directions colloiding in a random manner with one another and with the walls of the container and between two successive collisions molecules travel in a straight line path but show haphazard motion due to collisions.
3

### AIEEE 2002

Kinetic theory of gases proves
A
only Boyle's law
B
only Charle's law
C
D
All of these

## Explanation

Kinetic theory of gases proves all the given gas laws.
4

### AIEEE 2002

Value of gas constant R is
A
0.082 litre atm
B
0.987 cal mol-1 K-1
C
8.3 J mol-1 K-1
D
83 erg mol-1 K-1

## Explanation

Value of gas constant

$\left( R \right) = 0.0821L\,atm\,{K^{ - 1}}\,mo{l^{ - 1}}$

$= 8.314 \times {10^7}\,\,ergs\,{K^{ - 1}}\,mo{l^{ - 1}}$

$= 8.314J{K^{ - 1}}\,mo{l^{ - 1}}$

$= 1.987\,cal\,{K^{ - 1}}\,mo{l^{ - 1}}$