Category: HC Verma Part 1: Waves & Optics
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HC Verma Chapter 15 Problem 49 — reflected amplitude at density-change junction
Problem Statement Same string junction (densities $4\mu$ and $\mu$). Reflected amplitude? Given Information See problem statement for all given quantities. Physical Concepts & Formulas This problem applies fundamental physics principles to the scenario described. The solution requires identifying the relevant conservation laws and equations of motion, then solving systematically with careful attention to units and…
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HC Verma Chapter 15 Problem 50 — resultant amplitude with phase difference pi over 3
Problem Statement Two equal-amplitude waves, phase difference $\pi/3$. Resultant amplitude? Given Information See problem statement for all given quantities. Physical Concepts & Formulas This problem applies fundamental physics principles to the scenario described. The solution requires identifying the relevant conservation laws and equations of motion, then solving systematically with careful attention to units and sign…
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HC Verma Chapter 15 Problem 48 — transmitted amplitude at density-change junction
Problem Statement String: density $4\mu$ for $x 0$. Incident amplitude $A_i$. Transmitted amplitude? Given Information See problem statement for all given quantities. Physical Concepts & Formulas This problem applies fundamental physics principles to the scenario described. The solution requires identifying the relevant conservation laws and equations of motion, then solving systematically with careful attention to…
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HC Verma Chapter 15 Problem 47 — wavelength in new medium at boundary
Problem Statement Solve the oscillation/wave problem: Solve the oscillation/wave problem: Wave 500 Hz at 100 m/s enters medium where speed is 150 m/s. New wavelength? $f$ preserved at boundary; $\lambda=v/f$ Step 1: $f$ unchanged; $\lambda_2=150/500=0.3$ m. $$\boxed{\lambda_2=0.3\text{ m}}$$ Mass $m$ and spring constant $k$ (or equivalent), or wave par Given Information $\lambda_2=150/$ $\boxed{\lambda_2=0.3\text{ m}$ Physical…
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HC Verma Chapter 15 Problem 46 — average power in vibrating string
Problem Statement Solve the work-energy problem: Solve the work-energy problem: String: $\mu=0.2$ kg/m, $L=1$ m, $T=80$ N, amplitude 0.5 cm. Average power transmitted? $P=\frac{1}{2}\mu\omega^2 A^2 v$ Step 1: $v=\sqrt{80/0.2}=20$ m/s; $f_1=10$ Hz; $\omega=20\pi$ rad/s. Step 2: $P=\frac{1}{2}(0.2)(20\pi)^2(0.005)^2(20)\approx0.197$ W. $$\boxed{P\ap Given Information See problem statement for all given quantities. Physical Concepts & Formulas This problem applies…
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HC Verma Chapter 15 Problem 45 — nodes and antinodes in third harmonic
Problem Statement String 2 m fixed at both ends, 3rd harmonic. How many nodes and antinodes? Positions? Given Information See problem statement for all given quantities. Physical Concepts & Formulas This problem applies fundamental physics principles to the scenario described. The solution requires identifying the relevant conservation laws and equations of motion, then solving systematically…
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HC Verma Chapter 15 Problem 43 — wave speed from string fundamental
Problem Statement Solve the oscillation/wave problem: Solve the oscillation/wave problem: Guitar string: length 62.5 cm, fundamental 250 Hz. Wave speed? $v=2Lf_1$ Step 1: $v=2Lf_1=2\times0.625\times250=312.5$ m/s. $$\boxed{v=312.5\text{ m/s}}$$ Mass $m$ and spring constant $k$ (or equivalent), or wave parameters Initial conditions (amplitude $A$, phase Given Information $v=2Lf$ $v=2Lf$ $\boxed{v=312.5\text{ m/s}$ Physical Concepts & Formulas This problem…
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HC Verma Chapter 15 Problem 44 — effect of doubling tension on wave speed
Problem Statement Solve the oscillation/wave problem: Solve the oscillation/wave problem: Wave speed on string is 4 m/s. Tension doubled. New speed? $v\propto\sqrt{T}$ Step 1: $v\propto\sqrt{T}$; $v_2=4\sqrt{2}\approx5.66$ m/s. $$\boxed{v_2=4\sqrt{2}\approx5.66\text{ m/s}}$$ Mass $m$ and spring constant $k$ (or equivalent), or wave parameters Initial c Given Information $\boxed{v_2=4\sqrt{2}\approx5.66\text{ m/s}$ Physical Concepts & Formulas Newton’s second law $\mathbf{F}_\text{net} =…
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HC Verma Chapter 15 Problem 42 — Young modulus from longitudinal wave speed
Problem Statement Solve the oscillation/wave problem: Solve the oscillation/wave problem: Aluminum: $v_{sound}=5100$ m/s, $\rho=2700$ kg/m$^3$. Find Young’s modulus. $v=\sqrt{Y/\rho}$ in solids Step 1: $Y=\rho v^2=2700\times5100^2=7.02\times10^{10}$ Pa. $$\boxed{Y\approx7.0\times10^{10}\text{ N/m}^2}$$ Mass $m$ and spring constant $k$ (or equivalent), Given Information See problem statement for all given quantities. Physical Concepts & Formulas This problem applies fundamental physics principles…
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HC Verma Chapter 15 Problem 40 — fundamental frequency when length doubled tension halved
Problem Statement Solve the Newton’s Laws / mechanics problem: Solve the Newton’s Laws / mechanics problem: String fundamental 256 Hz. Length doubled, tension halved. New fundamental? $f\propto\sqrt{T}/L$ Step 1: $f=\frac{1}{2L}\sqrt{T/\mu}\propto\frac{\sqrt{T}}{L}$. Step 2: $f’=f\times\frac{1}{2}\times\frac{1}{\sqrt{2}}=256/(2\sqrt{2})\approx90.5$ Hz. $$\boxed Given Information $f’=f\times\frac{1}{2}\times\frac{1}{\sqrt{2}}=256/$ Physical Concepts & Formulas Newton’s second law $\mathbf{F}_\text{net} = m\mathbf{a}$ is the fundamental relation between net force…