A particle of mass $m_1$ is fastened to one end of a string and another particle of mass ${\mathrm{m}}_2$ is attached to the middle point, the other end of the string being fastened to a fixed point on a smooth horizontal table. If the particles are made to revolve in a horizontal circular path as shown in the figure, then the ratio of tension in the part of the string between the centre and $m_2$ to the tension in the part of the string between $m_2$ and $m_1$ is