In an arc welding process,two weld coupons were made using two different welding processes. For the first coupon, the voltage, current and welding speed used are 15 V, 300A
and 30 $$\frac{mm}{min}$$ respectively. Whereas the second couponis welded with 60 kV, 200 mA and 25 $$\frac{mm}{s}$$. If the heat transfer efficiency for welding the first coupon is half of that of second coupon, the ratio of heat input per unit lengthis?