In the equation below f is a frequency, and L is a length. What are the dimensions of a? In the equation below f is a frequency, and L is a length. What are the dimensions of a 1/f = 2.pi.root L/a Solution On the left hand side: Dimension of frequency is T-1. So, dimension of 1/f will be T. Now on the right hand side, 2pi is dimension less constant and L is length To obtain the dimension of T on the right side, we have to divide the length dimension by another length dimension and multiply by T2. Hence, dimension of 1/a = T2/L So, dimensions of a = L/T2 = LT-2.