Question

Use the circuit diagram to decide if the lightbulb will light. Justify your answer.

Answer 1

Answer:

The lightbulb will NOT light.

Explanation:

You put me in a difficult position.  I can't help it, but the "sample answer" is by far the best way to explain this, briefly and correctly.  There's no other choice but to copy it.

This is a short circuit. The branch without the bulb has almost no resistance, so all the current will flow through that branch instead of flowing through the bulb.

If the lower switch were opened, THEN we would have a series circuit.  Current would no longer have any other choice but to flow through the bulb, and the bulb would light.

Answer 2

Answer:

Sample Response: The lightbulb will not light because this is a short circuit. The branch without the bulb has almost no resistance, so all the current will flow through that branch instead of flowing through the bulb.