Question

One summer i installed some decorative low voltage lighting (15 volt) around my patio. the lights are wired in parallel. the manufacturer says that the power supply can safely deliver 8 a of current. how many 18 watt lights can i attach to a single power supply?

Answer 1

First, we determine the power that the assembly can supply by multiplying the voltage by the current. That is,

Power = voltage x current

Substituting the known values,

P = (15 V)(8 a)
P = 120 watts

To determine the answer to this item, we divide the calculate power of each,

n = 120 watts / 18 watt/light
n = 6.67 lights

The answer to this item is 6.