Concepts Of Physics MCQ Edition [Volume 1]PhysicsWave Motion and Waves on a String
One end of a string having a total length of 30 cm and a linear mass density of 0.5 g cm ⁻¹ is fixed to a wall, and the other end is attached to a frictionless ring that slides on a vertical rod. A wave pulse moves along the string towards the ring at a speed of 20 cm s ⁻¹ . The pulse is symmetric about its maximum, initially located 20 cm from the ring. Assuming no energy is lost during reflections at the ends, what
Options
- A5 10⁻⁴ N
- B4 10⁻³ N
- C2 10⁻³ N
- D2 10⁻² N
Correct answer
C. 2 10⁻³ N
Step-by-step solution
Given, linear mass density of the string, = 0.5 g cm ⁻¹ . Converting to SI units: = 0.5 10⁻³ kg 10⁻² m = 0.05 kg m ⁻¹ Speed of the wave pulse, v = 20 cm s ⁻¹ = 0.2 m s ⁻¹ . The speed of a transverse wave on a stretched string is given by the relation: v = T Rearranging the formula to solve for tension T : T = v^2 Substituting the given values: T = 0.05 (0.2)^2 T = 0.05 0.04 T = 0.002 N = 2 10⁻³ N