JEE Main Physics question
A spring when stretched by 2 mm has potential energy 4 J. If it is stretched by 10 mm, its potential energy is equal to
Answer: (D)
Solution
Since U ∝ x², U₂ = U₁(x₂/x₁)² = 4 × (10/2)² = 4 × 25 = 100 J. As 100 J is not among options (A)–(C), the answer is (D) None.