Question

Rigidity modulus of steel is $\eta$ and its Young’s modulus is $Y$. A piece of steel of cross-sectional area ${}^{\prime }{A}^{\prime }$ is changed into a wire of length $L$ and area $A/10$ then:

• A. $Y$ and $\eta$ remain the same"
• B. both $Y$ and $\eta$ increase
• C. $Y$ increases and $\eta$ decreases
• D. both $Y$ and $\eta$ decrease

Answer 1

The correct option is A $Y$ and $\eta$ remain the same"

As given in question, $\eta$ and $Y$ are rigidity and Young’s modulus of steel.
As we know, material property does not depend on dimensions of object i.e., $\eta$ and $Y$ should not change whether its length changes or not.
Hence,$\eta$ and $Y$ remains same and does not feel and changes.