. A section (PQRS) of current (1) carrying wire is platted in a uniform magnetic field (B) as shown below. in the length of the section is L, then the magnitude of magnetic force on the wire is X

To calculate the magnetic force on a current-carrying wire in a magnetic field, you can use the formula: \[ F = I \cdot L \cdot B \cdot \sin(\theta) \] where: - \( F \) is the magnetic force, - \( I \) is the current flowing through the wire, - \( L \) is the length of the wire in the magnetic field, - \( B \) is the magnetic field strength, and - \( \theta \) is the angle between the wire and the magnetic field. If the wire section PQRS is perpendicular to the magnetic field, then \( \theta = 90^\circ \) and \(\sin(90^\circ) = 1\). Therefore, the formula simplifies to: \[ F = I \cdot L \cdot B \] If the angle is different, you would need to know \( \theta \) to calculate \( F \) correctly. Assuming \( I = 1 \, \text{A} \), \( L = L \, \text{m} \), and \( B = B \, \text{T} \), you can substitute these values into the formula to get: \[ F = 1 \cdot L \cdot B = L \cdot B \] Thus, the magnitude of the magnetic force on the wire is \( X = L \cdot B \) if the current is 1 A and the angle is 90 degrees. If the angle or other values change, you will need to adjust the calculation accordingly.