Work speed of circular electrode of 220 mm diameter for carrying out seam welding at 4 welds per cm on 1.6 mm thick mild steel tube. Welding cycle consists of 3 cycles ‘on’ and 2 cycles ‘off’ Power supply is at 50 Hz. Calculate R.P.M. and energy requirement of the above circular electrodes assuming effective resistance between electrodes as 100 ohm.

• A. 22 rpm, 600 joules
• B. 2.17 rpm, 600 joules
• C. 5.03 rpm, 600 joules
• D. 6.8 rpm, 6 joules

Answer: (B)