JEE Main On 16 April 2018 Question 20
Question: Two moles of helium are mixed with moles of hydrogen. If $ \frac{C _{P}}{C _{V}}=\frac{3}{2} $ for the mixture, then the value of n is [JEE Main 16-4-2018]
Options:
A) 3/2
B) 2
C) 1
D) 3
Show Answer
Answer:
Correct Answer: B
Solution:
For a given mixture of gases,
$ (n _1+n _2)/(\lambda -1)=n _1/(Y _1-1)+n _2/(Y _2-1) $
Put $ n _1=2,Y=3/2,Y _1=5/3,Y _2=7/5 $
solving the required equation as
$ (2+n)/(3/2-1)=2/(5/3-1)+n/(7/5-1) $ $ n=2 $
