One pair of ends of two long, parallel wires are connected by a resistor, R = 0.25 W, and a fuse that will break instantaneously if 5 amperes of current passes through it. The other pair of ends are unconnected. A conducting rod of mass m is free to slide along the wires under the influence of gravity. The wires are separated by 30 cm and the rod starts out 10 cm from the resistor and fuse. The whole system is placed in a uniform, constant magnetic field of B = 1.2T as shown in the figure. The resistance of the rod and the wires is negligible. When the rod is released it falls under the influence of gravity, but never loses contact with the long parallel wires. The smallest mass m of the rod needed to break the fuse is found to be :

       m = 2n × 10^–2 kg .

Find the integer n ? (g = 10 ms^–2)