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Torques tau(1) and tau(2) are required f...

Torques `tau_(1)` and `tau_(2)` are required for a magnetic needle to remain perpendicular to the magnetic fields at two different places. The magnetic field at those places are B1 and B2 respectively, then `(B_(1))/(B_(2))` is

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To solve the problem, we need to analyze the relationship between the torques acting on a magnetic needle in two different magnetic fields. Here's a step-by-step solution: ### Step 1: Understanding Torque The torque (\( \tau \)) on a magnetic needle in a magnetic field is given by the formula: \[ \tau = \mathbf{m} \times \mathbf{B} \] Where: - \( \tau \) is the torque, - \( \mathbf{m} \) is the magnetic moment of the needle, - \( \mathbf{B} \) is the magnetic field. ### Step 2: Torque When Needle is Perpendicular When the magnetic needle is perpendicular to the magnetic field, the angle \( \theta \) between the magnetic moment and the magnetic field is \( 90^\circ \). Therefore, the sine of \( 90^\circ \) is 1. Thus, the torque can be simplified to: \[ \tau = mB \sin(90^\circ) = mB \] ### Step 3: Expressing Torques for Two Different Fields Let \( \tau_1 \) be the torque required for the magnetic needle to remain perpendicular in the magnetic field \( B_1 \), and \( \tau_2 \) be the torque in the magnetic field \( B_2 \). We can express these as: \[ \tau_1 = mB_1 \] \[ \tau_2 = mB_2 \] ### Step 4: Finding the Ratio of the Magnetic Fields To find the ratio of the magnetic fields \( \frac{B_1}{B_2} \), we can set up the following equation using the expressions for \( \tau_1 \) and \( \tau_2 \): \[ \frac{\tau_1}{\tau_2} = \frac{mB_1}{mB_2} \] Since the magnetic moment \( m \) is constant for the same needle, it cancels out: \[ \frac{\tau_1}{\tau_2} = \frac{B_1}{B_2} \] ### Step 5: Conclusion Thus, we can conclude that: \[ \frac{B_1}{B_2} = \frac{\tau_1}{\tau_2} \] ### Final Answer The ratio of the magnetic fields \( \frac{B_1}{B_2} \) is equal to the ratio of the torques \( \frac{\tau_1}{\tau_2} \). ---

To solve the problem, we need to analyze the relationship between the torques acting on a magnetic needle in two different magnetic fields. Here's a step-by-step solution: ### Step 1: Understanding Torque The torque (\( \tau \)) on a magnetic needle in a magnetic field is given by the formula: \[ \tau = \mathbf{m} \times \mathbf{B} \] Where: ...
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