Task id16541

What length l should a nichrome conductor with a cross-section S = 0.1 mm2 be taken to make a heater on which a volume of water V = 1.5 liters taken at a temperature t1 = 20°C can be brought to a boil in a time t = 5 minutes ? Mains voltage U = 220 V. Efficiency boiler h = 90%. The resistivity of nichrome is p = 1.10 μOhm m.