Which component uses low amperage to operate a high amperage component?

Which component uses low amperage to operate a high amperage component?

• A. The ignition switch
• B. The start switch and crank relay
• C. The battery cable
• D. The cam sensor

Answer: (B)

The idea is using a low-current control to switch a high-current device. In starting circuits, a small current from the start switch energizes a crank relay (solenoid). The relay’s coil draws little current, but it closes heavy-duty contacts that carry the large current from the battery to the starter motor. This lets a simple switch control a high‑current load safely. The ignition switch by itself isn’t meant to carry the starter’s high current, the battery cable is just a power path, and the cam sensor is a low-current sensor, not a device that switches high current to a motor. So the combination of the start switch and crank relay best fits the scenario of using low amperage to operate a high amperage component.

The idea is using a low-current control to switch a high-current device. In starting circuits, a small current from the start switch energizes a crank relay (solenoid). The relay’s coil draws little current, but it closes heavy-duty contacts that carry the large current from the battery to the starter motor. This lets a simple switch control a high‑current load safely.

The ignition switch by itself isn’t meant to carry the starter’s high current, the battery cable is just a power path, and the cam sensor is a low-current sensor, not a device that switches high current to a motor. So the combination of the start switch and crank relay best fits the scenario of using low amperage to operate a high amperage component.