Question

Will it affect the brightness of the lightbulb?

Answer 1

Yes. Both nodes of the bulb are at the same potential and therefore no current will flow through it. The bulb will go out.

Answer 2

awesome, thanks

Answer 3

@Matt71 current has two paths
one with the bulb which has a resistance
second path with no resistance
so it'll take the second path and hence the bulb's won't have any current through it. And it won't glow