Physics · PYQ NEET UG 2023
हिन्दीThe potential energy of a long spring when stretched by \( 2\text{ cm} \) is \( U \). If the spring is stretched by \( 8\text{ cm} \), potential energy stored in it will be :
Correct answer · Option 4
\( 16U \)
Explanation
Potential energy \( U = \frac{1}{2}kx^2 \). Since \( U \propto x^2 \), when \( x \) increases from \( 2\text{ cm} \) to \( 8\text{ cm} \) (4 times), energy becomes \( 4^2 = 16 \) times, i.e., \( 16U \).