Новое решение
en/11.5.23.md
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| + | ### Statement | ||
| + | |||
| + | $11.5.23.$ [Insert the problem statement] | ||
| + | |||
| + | ### Solution | ||
| + | |||
| + | The oscillation period of a conventional torsional pendulum with a small amplitude is: | ||
| + | |||
| + | $$T = 2\pi \sqrt{\frac{J}{k}}$$ | ||
| + | |||
| + | Where $k$ is the torsional stiffness of the thread, we express it: | ||
| + | |||
| + | $$k = \frac{4 \pi^2 J}{T^2}$$ | ||
| + | |||
| + | The moment acting on the frame from the side of the magnetic field is equal to: | ||
| + | |||
| + | $$M = \mu \times B \approx \mu B$$ | ||
| + | |||
| + | where $\mu = \pi r^2i$ is the magnetic moment of the frame. | ||
| + | |||
| + | The magnetic flux through the frame is: | ||
| + | |||
| + | $$\Phi = L I = B \pi r^2 \varphi$$ | ||
| + | |||
| + | $$I = \frac{B \pi r^2}{L} \varphi$$ | ||
| + | |||
| + | Let's make up the equation of oscillations in 2ZN for rotational motion: | ||
| + | |||
| + | $$J \beta = k = \frac{4 \pi^2 J}{T^2} \varphi + \frac{B^2 \pi^2 r^4}{L} \varphi$$ | ||
| + | |||
| + | The period is similar to the usual fluctuations, after the transformations: | ||
| + | |||
| + | $$T' = \frac{T}{\sqrt{1+\frac{B^2 r^4 T^2}{4LJ}}}$$ | ||
| + | |||
| + | #### Answer | ||
| + | |||
| + | [Insert a concise answer or boxed result] | ||
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| ### Statement | |||
| $11.5.23.$ [Insert the problem statement] | |||
| ### Solution | |||
| The oscillation period of a conventional torsional pendulum with a small amplitude is: | |||
| $$T = 2\pi \sqrt{\frac{J}{k}}$$ | |||
| Where $k$ is the torsional stiffness of the thread, we express it: | |||
| $$k = \frac{4 \pi^2 J}{T^2}$$ | |||
| The moment acting on the frame from the side of the magnetic field is equal to: | |||
| $$M = \mu \times B \approx \mu B$$ | |||
| where $\mu = \pi r^2i$ is the magnetic moment of the frame. | |||
| The magnetic flux through the frame is: | |||
| $$\Phi = L I = B \pi r^2 \varphi$$ | |||
| $$I = \frac{B \pi r^2}{L} \varphi$$ | |||
| Let's make up the equation of oscillations in 2ZN for rotational motion: | |||
| $$J \beta = k = \frac{4 \pi^2 J}{T^2} \varphi + \frac{B^2 \pi^2 r^4}{L} \varphi$$ | |||
| The period is similar to the usual fluctuations, after the transformations: | |||
| $$T' = \frac{T}{\sqrt{1+\frac{B^2 r^4 T^2}{4LJ}}}$$ | |||
| #### Answer | |||
| [Insert a concise answer or boxed result] | |||