Two 1 mm thick steel sheets are to be spot welded at a current of 5000 A. Assuming effective resistance to be 200 μm and current flow time of 0.2 second, heat generated during the process will be
Answer: D
Given: I = 5000 A, R = 200 μΩ = 200 × 10⁻⁶ Ω, Δt = 0.2 second
Heat generated, Hg = I 2(R Δt)
Hg = (5000)⊃2; × 200 × 10⁻⁶ × 0.2 = 1000 Joule