Question

which of the following applies when the circuit is on in a ground - side switched circuit?
a) there is voltage until after the switch.
b) current is consumed by the load.
c) there is voltage until after the load.
d) voltage returns to ground.

Explanation:

In a ground - side switched circuit, when the circuit is on:

• Option A: In a ground - side switched circuit, voltage is present before the switch (source side). After the switch (when it is on), since it is a ground - side switch, the path to ground is completed. So, there is not voltage after the switch in the sense of a potential difference for current flow in that part (it is at ground potential).
• Option B: When the circuit is on, the load (e.g., a light bulb, motor etc.) consumes electrical energy. According to the formula \(P = VI\) (power = voltage×current), current is used by the load to do work (such as converting electrical energy to light and heat for a bulb).
• Option C: After the load, in a ground - side switched circuit (when the switch is on), the current has completed its path through the load and is going to ground. There is no voltage after the load in terms of a potential difference for current flow (it is at ground potential)
• Option D: In a ground - side switched circuit, when the switch is on, current (not voltage) returns to ground. Voltage is a potential difference.

Answer:

B. Current is consumed by the load.