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The lengths of two wires of same materia...

The lengths of two wires of same material are in the ratio 1:2, their tensions are in the ratio 1:2 and their diameters are in the ratio 1:3. the ratio of the notes they emits when sounded together by the same source is

A

`sqrt(2)`

B

`sqrt3`

C

`2sqrt(3)`

D

`3sqrt(2)`

Text Solution

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The correct Answer is:
To solve the problem, we need to find the ratio of the frequencies of two wires made of the same material, given the ratios of their lengths, tensions, and diameters. ### Step-by-Step Solution: 1. **Understanding the Frequency Formula**: The frequency \( f \) of a wire is given by the formula: \[ f = \frac{V}{2L} \] where \( V \) is the velocity of the wave in the wire and \( L \) is the length of the wire. 2. **Velocity of the Wave**: The velocity \( V \) can be expressed in terms of tension \( T \) and linear mass density \( \mu \): \[ V = \sqrt{\frac{T}{\mu}} \] Therefore, the frequency can be rewritten as: \[ f = \frac{1}{2L} \sqrt{\frac{T}{\mu}} \] 3. **Linear Mass Density \( \mu \)**: The linear mass density \( \mu \) is defined as: \[ \mu = \frac{m}{L} = \text{Area} \times \text{Density} \] For a wire with diameter \( d \): \[ \text{Area} = \frac{\pi d^2}{4} \] Thus, we can write: \[ \mu = \frac{\pi d^2}{4} \cdot \rho \] where \( \rho \) is the density of the material. 4. **Finding the Frequencies**: For the first wire (Wire 1): \[ f_1 \propto \frac{1}{2L_1} \sqrt{\frac{T_1}{\mu_1}} \] For the second wire (Wire 2): \[ f_2 \propto \frac{1}{2L_2} \sqrt{\frac{T_2}{\mu_2}} \] 5. **Setting Up the Ratios**: Given: - Lengths: \( L_1 : L_2 = 1 : 2 \) (i.e., \( L_2 = 2L_1 \)) - Tensions: \( T_1 : T_2 = 1 : 2 \) (i.e., \( T_2 = 2T_1 \)) - Diameters: \( d_1 : d_2 = 1 : 3 \) (i.e., \( d_2 = 3d_1 \)) The linear mass densities can be expressed as: \[ \mu_1 = \frac{\pi d_1^2}{4} \cdot \rho \quad \text{and} \quad \mu_2 = \frac{\pi d_2^2}{4} \cdot \rho = \frac{\pi (3d_1)^2}{4} \cdot \rho = \frac{9\pi d_1^2}{4} \cdot \rho \] 6. **Calculating the Frequency Ratio**: The ratio of frequencies \( \frac{f_1}{f_2} \) can be expressed as: \[ \frac{f_1}{f_2} = \frac{\sqrt{T_1/\mu_1}}{\sqrt{T_2/\mu_2}} \cdot \frac{L_2}{L_1} \] Substituting the ratios: \[ \frac{f_1}{f_2} = \frac{\sqrt{T_1}}{\sqrt{2T_1}} \cdot \frac{L_2}{L_1} \cdot \frac{\sqrt{\mu_2}}{\sqrt{\mu_1}} = \frac{1}{\sqrt{2}} \cdot \frac{2L_1}{L_1} \cdot \frac{3}{1} \] Simplifying gives: \[ \frac{f_1}{f_2} = \frac{3}{\sqrt{2}} \] 7. **Final Result**: Therefore, the ratio of the frequencies is: \[ \frac{f_1}{f_2} = 3\sqrt{2} \]

To solve the problem, we need to find the ratio of the frequencies of two wires made of the same material, given the ratios of their lengths, tensions, and diameters. ### Step-by-Step Solution: 1. **Understanding the Frequency Formula**: The frequency \( f \) of a wire is given by the formula: \[ f = \frac{V}{2L} ...
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