What aspect does the left hand rule help to determine about a conductor?

The left-hand rule is a fundamental principle in physics that specifically helps to determine the direction of the magnetic force acting on a current-carrying conductor in a magnetic field. According to this rule, if you align your left hand such that the thumb points in the direction of the current and the fingers point in the direction of the magnetic field, the force experienced by the conductor will be directed outwards from the palm of the hand.

This principle is particularly useful in applications such as electric motors, where understanding the interaction between magnetic fields and electric currents is essential to predicting how the motor will function. The other options do not pertain to the left-hand rule; for instance, the rate of conductance, resistance level, and current capacity involve principles related to Ohm's law and material properties, rather than the directional relationship between current and magnetic fields represented by the left-hand rule.