Why is the dimensions of pressure head equal to the dimensions of length when pressure head is pressure per unit volume? Share with your friends Share 0 Aarushi Mishra answered this No pressure head is not pressure per unit volume. It is defined as follows ψ=pγψ=pγRefer above for definition of p and γNewton→MLT-2Pressure→ML-1T-2ψ=ML-1T-2ML-1T-2L-3ψ=ML-1T-2ML-2T-2ψ=M1-1L-1--2T-2--2ψ=M0L1T0 1 View Full Answer