Question

Assertion (A):When a spring is cut into two equal parts, spring constant of each piece is doubled.
Reason (R): Spring constant is inversely proportional to length of spring

• A. Both A and R are true and R is the correct explanation of A
• B. Both A and R are true and R is not the correct explanation of A
• C. A is true and R is false
• D. A is false and R is true

Answer 1

The correct option is A Both A and R are true and R is the correct explanation of A

Even when the spring is cut into two halves the Young's modulus E and Area of cross section remain the same
$K=\frac{EA}{l}$
When cut to half $l$ becomes $\frac{l}{2}$
thus $K_1=\frac{2EA}{l}=2k$
$K_1=2k$