Question

Assertion (A) : Lead is more elastic than rubber.
Rekson (R) : If the same load is attached to lead and rubber wires of the same cross sectional area,the strain of lead is very much less than that of rubber.

• A. Both assertion and reason are true and the reason is correct explanation of the assertion
• B. Both assertion & reason are true, but reason is not correct explanation of the assertion
• C. Assertion is true, but the reason is false
• D. Assertion is false but the reason is true

Answer 1

Answer: (A)

On applying load on lead and rubber wires of same cross-secion area, the strain produced in lead is much less than rubber wires. Now from the relation, $Y=$ Young's modulus
or $Y=\frac{\text { stress }}{\text { strain }}$
The Young's modulus of elasticity of elasticity is grater for lead wires. Hence, lead is elastic than rubber.