The formula for calculating coil force of magnetic field is F = nIB, where F is the force, n is the number of turns in the coil, I is the current in the coil, and B is the magnetic field strength.
The direction of the force applied on the object can be determined using the right-hand rule. Point your thumb in the direction of the current flow, your index finger in the direction of the magnetic field, and your middle finger will point in the direction of the force.
The strength of the magnetic field is affected by the number of turns in the coil, the current flowing through the coil, and the strength of the permanent magnet used to create the magnetic field.
The force on the object can be increased by increasing the number of turns in the coil, increasing the current flowing through the coil, or using a stronger permanent magnet to create the magnetic field.
The approach for moving an object using coil force of magnetic field involves creating a magnetic field using a permanent magnet, placing the coil with a current in the magnetic field, and adjusting the factors (number of turns, current, and strength of the magnet) to achieve the desired force and movement of the object.