A solid cylinder of diameter 100 mm and height 50 mm is forged between two frictionless flat dies to a height of 25 mm. The percentage change in diameter is
Answer: D
Since volume of cylinder remains same.
Therefore, Volume before forging = Volume after forging
πd₁⊃2;/ 4 = πd₂⊃2;/ 4
Or, d₂ = 141.42
Percentage change in diameter = {(d₂ - d₁)/ d₁} × 100
= 41.42%