The value of Poisson's ratio for cast iron is in the range of
- A0.09 - 0.19
- B0.20 - 0.30Correct
- C0.31 - 0.41
- D0.42 - 0.52
Solution
Concept
Poisson's ratio of cast iron is about 0.21 to 0.27, so it lies in the 0.20 - 0.30 range.
Formula
μ = lateral strain / longitudinal strain
Step-by-step solution
1. Recall typical Poisson's ratio values: steel about 0.27 - 0.30, concrete about 0.1 - 0.2, cast iron about 0.21 - 0.27. 2. The cast iron range fits inside 0.20 - 0.30. 3. So the answer is option B.
Explanation
Poisson's ratio is lateral strain divided by longitudinal strain. For cast iron its value is about 0.21 to 0.27. This range falls in option B.
Why the other options are wrong
A: 0.09 - 0.19 is too low (closer to concrete). C: 0.31 - 0.41 suits metals like aluminium or copper, not cast iron. D: 0.42 - 0.52 is near rubber (about 0.5), far too high.
Shortcut
Most engineering metals have μ between 0.25 and 0.35. Cast iron is at the lower end, about 0.25.
Common mistake
Mixing up cast iron with concrete (about 0.15) or with aluminium (about 0.33).
Correct answer: B) 0.20 - 0.30