Question

Spot welding of two steel sheets each $2mm$ thick is carried out successfully by passing $4kA$ of current of $0.2$ seconds through the electrodes. The resulting weld nugget formed between the sheets is $5mm$ in diameter. Assuming cylindrical shaper for the nugget, the thickness of the nugget is

• A. 2.91

Answer 1

The correct option is A 2.91
$\text{Given data:}$

$t=2mm,I=4kA,\text{Time}=0.2s$

$D_N=5mm$

$I^{2}Rt=\text{Volume}\times \rho \times \text{H.R/kg}$

${4000}^2\times 200\times {10}^{-6}\times 0.2=Vol.\times 8000\times 1400\times {10}^3$

$h=2.91mm$