What component prevents the voltage in an ignition system from arcing across the breaker points?

The correct answer is the condenser. In an ignition system, the condenser, also known as a capacitor, serves a crucial role in helping to prevent arcing at the breaker points. When the ignition points open to interrupt the flow of current, the rapid change in current can cause a high-voltage arc across the points, leading to excessive wear or damage. The condenser temporarily stores electrical energy and releases it quickly, which helps to eliminate the high-voltage spike that would otherwise cause arcing. By managing the electrical discharge and smoothing out the current flow when the points open, the condenser ensures that the ignition system functions reliably and efficiently.

The coil, though vital to generating high voltage for spark creation, does not directly prevent arcing at the points. The distributor cap directs the high-voltage current to the appropriate spark plug but does not play a role in controlling the arcing at the breaker points. The ignition switch, which controls the power to the ignition system, is not involved in the operation of the breaker points itself. Each of these components has a specific function, but the prevention of arcing is uniquely the responsibility of the condenser.