The correct answer is C. Magnetomotive force (MMF) is the magnetic equivalent of voltage in an electrical circuit. It is the force that drives the magnetic flux through a magnetic circuit. The MMF is proportional to the number of turns in the coil and the current through the coil.
Flux density (B) is the measure of the strength of the magnetic field at a point. It is proportional to the MMF and inversely proportional to the reluctance of the magnetic circuit.
The number of lines of force is a measure of the total magnetic flux through a magnetic circuit. It is proportional to the flux density and the cross-sectional area of the magnetic circuit.
Reluctance (R)
is the magnetic equivalent of resistance in an electrical circuit. It is a measure of the opposition to the flow of magnetic flux through a magnetic circuit. It is proportional to the length of the magnetic circuit and inversely proportional to the permeability of the magnetic material.None of the above options is directly comparable to voltage in an electrical circuit.