JEE Main 2022 · 26 July · morning · Single correct · +4 / −1
When a particle executes Simple Hormonic Motion, the nature of graph of velocity as a function of displacement will be :
- (a) Circular
- (b) Elliptical
- (c) Sinusoidal
- (d) Straight line
Answer and solution
Answer (b) Elliptical
Solution
Physics sir · 3 steps
Eliminate time between x and v, and the equation that drops out is an ellipse.
- Write x and v. Take x = A sin ω t. Differentiating gives v = Aω cos ω t.
- Remove time. Use sin² ω t + cos² ω t = 1, with sin ω t = x/A and cos ω t = v/(Aω).
x²/A² + v²/A²ω² = 1
- So. This is an ellipse with semi-axes A along x and Aω along v. The answer is (b).
The idea to keep. A graph of one quantity against another, with no time axis, needs time eliminated. In SHM, v against x and a against v both give ellipses, while a against x is a straight line.
Answer from the NTA final answer key. Solution by PrepWiser.