Q. 17 What is the Young's modulus for a perfect rigid body.

Hint: In a perfect rigid body, the distance between any two points does not change.
Step 1: Find the Young's modulus of a perfect rigid body.
Young's modulus (Y) = FA×ll
For a perfectly rigid body, the change in length, l=0
                                                  Y=FA×l0=
Therefore, Young's modulus for a perfectly rigid body is infinite().