What increases the relatively low voltage produced in the primary coil windings of a magneto?

The increase in voltage produced in the primary coil windings of a magneto is primarily attributed to the induced voltage in the secondary circuit. In a magneto, when the magnetic field around the coil changes, it induces a voltage due to electromagnetic induction. The primary coil generates a relatively low voltage, but when this voltage is transferred to the secondary coil, where the turns of wire are often significantly higher, the resulting voltage is much greater. This process works according to the principle that the voltage is proportional to the number of turns in the coil. Therefore, because the secondary circuit typically consists of more turns than the primary, the induced voltage in the secondary is greater, leading to a higher output voltage that can be utilized for ignition or other applications.

The other choices do not effectively describe the mechanism that enhances the voltage in this context. Resistor action refers to the energy dissipation in resistors, which would not increase voltage. Battery power is not a factor in the operation of a magneto since it relies on magnetic induction rather than an external power source. Capacitor discharge is related to the release of stored energy in a capacitor, which again does not apply to the primary process of voltage induction in a magneto.