A 440 volts, 50Hz, 6 pole, star connected required cage induction motor has the following parameters Rs = 0.6omh, Rr = 0.3 ohm Xs = Xr = 1 ohm. The normal full load slip is 0.05 The motor is fed from a voltage source inverter, which maintains constant v/f ratio. For an operating frequency of 10Hz, calculate the break down torque as a ratio of its value at rated torque as frequency.