Verified Solution • 2025–26 Session moderate

Q14.1: WAVES Solutions — NCERT Physics - Part 2

⚠️ Common Exam Traps & Conceptual Pitfalls

Students frequently forget to divide the total mass by the total length to find the linear mass density ($\mu$), or they incorrectly substitute the total mass directly into the wave velocity formula. Always calculate $\mu = M/l$ first before applying $v = \sqrt{T/\mu}$.

A string of mass 2.50 kg is under a tension of 200 N. The length of the stretched string is 20.0 m. If the transverse jerk is struck at one end of the string, how long does the disturbance take to reach the other end?

Step-by-Step Verified Solution

**Answer:**

t = 0.5 \text{ s}

**Step-by-Step Explanation:** Given: mass

M = 2.50

kg, tension

T = 200

N, length

l = 20.0

m. Linear mass density:

\mu = \frac{M}{l} = \frac{2.50}{20.0} = 0.125 \text{ kg/m}

Velocity of transverse wave:

v = \sqrt{\frac{T}{\mu}} = \sqrt{\frac{200}{0.125}} = \sqrt{1600} = 40 \text{ m/s}

Time taken:

t = \frac{l}{v} = \frac{20.0}{40} = 0.5 \text{ s}

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All Questions in this Chapter

Q14.1 Q14.2 Q14.3 Q14.4 Q14.5 Q14.6 Q14.7 Q14.8 Q14.9 Q14.10 Q14.11 Q14.12 Q14.13 Q14.14 Q14.15 Q14.16 Q14.17 Q14.18 Q14.19

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