Q.

What is the dimensional formula of ab-1 in the equation (P+aV2)(V-b)=RT, where letters have their usual meaning.        [2024]

1 [M6L7T4]  
2 [ML2T-2]  
3 [M-1L5T3]  
4 [M0L3T-2]  

Ans.

(2) 

      [V]=[b] It means the dimension of b=[L3]

      [P]=[aV2][a]=[PV2]=[ML-1T-2][L6]

      Dimension of a=[ML5T-2]

         ab-1=[ML5T-2][L3]=[ML2T-2]