What is the dimensional formula of ab-1 in the equation (P + aV2 )(V - b) = RT, where letters have their usual meaning.
- [M6 L7 T4]
- [ M-1 L5 T3]
- [ M0 L3 T-2]
- [ M L2 T-2]
Answer
(4) [ M L2 T-2]
Solution
only quantities of the same dimensions can be added or subtracted:
[ aV2 ] = [P] [a] = [P][V2] = ML-1T-2 L6 = ML5T-2
[b] = [V] = L3
[ab-1] = ML5T-2L3 = [ ML2T-2] (dimensions of energy)
Answer: (4)