The armature moves along parallel rails at a constant speed v, which is ensured by the appropriate external force. The circuit A is short-circuited on the left with a resistor of resistance R. The rails on the left side have the opening lL = l and on the right side lR = 1.5 * l. In both systems, the armatures move without friction, the rails and armatures have zero resistance, and both systems are placed in a constant magnetic field with a magnetic induction B perpendicular to the plane of the drawing. Calculate how many times greater is the value of the external force pulling the armature in system B than the external force in system A.

The armature moves along parallel rails at a constant speed v, which is ensured by the appropriate external force. The circuit A is short-circuited on the left with a resistor of resistance R. The rails on the left side have the opening lL = l and on the right side lR = 1.5 * l. In both systems, the armatures move without friction, the rails and armatures have zero resistance, and both systems are placed in a constant magnetic field with a magnetic induction B perpendicular to the plane of the drawing. Calculate how many times greater is the value of the external force pulling the armature in system B than the external force in system A.