Physics Circle home Student Login

Home›Chapters›Wave Motion PYQs›Stationary Waves & Vibrating Strings›Question 94

JEE Main 2019 (10 Jan, Shift 1) · Stationary Waves & Vibrating Strings

Stationary Waves & Vibrating Strings question from JEE Main 2019 (10 Jan, Shift 1)

Q94JEE Main 2019 · 10 JAN · SHIFT 1Medium

Stationary Waves & Vibrating Strings

A string of length 1 m and mass 5 g is fixed at both ends. The tension in the string is 8.0 N. The string is set into vibration using an external vibrator of frequency 100 Hz. The separation between successive nodes on the string is close to -

Show answer and solution

Answer: (c)

  1. μ=5×10−31=5×10−3 kg/m\mu = \dfrac{5\times10^{-3}}{1} = 5\times10^{-3}\text{ kg/m}, v=85×10−3=40 m/sv = \sqrt{\dfrac{8}{5\times10^{-3}}} = 40\text{ m/s}.
  2. The string vibrates at the driver frequency: λ=vn=40100=0.4 m\lambda = \dfrac{v}{n} = \dfrac{40}{100} = 0.4\text{ m}.
  3. Successive nodes are λ2=0.2 m=20 cm\dfrac{\lambda}{2} = 0.2\text{ m} = 20\text{ cm} apart.
  4. So the answer is (c) 20.0 cm.
Report a mistake

More questions on Stationary Waves & Vibrating Strings