Review deformation of solids

Hooke's law holds good up to

• elastic limit

• breaking point

• yield point

• proportionality limit

• A

• B

• C

• D

What is the formula for Young Modulus?

• F = kx
  

If the length of wire, as stretched by a load is doubled, then it's Young's modulus will be

• doubled

• halved

• becomes four times

• unaffected

If the material recovers the original dimensions, when an external load is removed, this deformation is known as ______ deformation

• plastic

• permanent

• elastic

• reversible

Which statement describes what is meant by the plastic deformation of a material?

• It always obeys Hooke’s law.

• It does not return to its original length when the extending force is removed

• It never obeys Hooke’s law

• It returns to its original length when the extending force is removed.

Which force-extension graph shows plastic deformation of a sample of material?

• 
• 
• 
• 

When the sample contracts, it follows the same force-extension curve as when it was being

stretched.

What is the behaviour of the metal between X and Y?

• both elastic and plastic

• not elastic and not plastic

• plastic but not elastic

• elastic but not plastic

Identical springs are joined in four arrangements.

Which arrangement has the same spring constant as a single spring?

• 
• 
• 
• 

What is the area under graph for stress versus strain .....

• spring constant, k

• strain energy per unit volume,

• strain energy, U

• elongation, e

• no area under graph