What calculation is used to ensure that the current draw of an audible device does not exceed the control panel's rated alarm output?

• A. Kirchhoff's Law
• B. Ohm's Law
• C. Newton's Law
• D. Boyle's Law

Answer: (B)

The key idea is using Ohm's Law to size the load. To prevent the audible device from drawing more current than the control panel can supply, you compare the panel’s output voltage with the device’s impedance (or resistance) to find the current it will draw: I = V / R. If that current is at or below the panel’s rated alarm output, the device can be connected; if it’s higher, you need a relay or separate power interface to protect the panel. Ohm's Law directly links the supply voltage, the device's impedance, and the resulting current, which is exactly what you need for this check. Kirchhoff's Law deals with currents and voltages in a circuit as a whole, not the specific current draw of a single load; Newton's and Boyle's laws are for mechanics and gases, not electrical load sizing.