The rheostat and the brightness of the bulbs

[Asmaa Mohammad]

Homework Statement

In the circuit shown in the figure, what will happen to the brightness of bulb A and bulb B when the wiper moves from point X to point Y?

Homework Equations

The Attempt at a Solution

[/B]
When the wiper moves towards Y we get smaller resistance, hence the current intensity rises, so the brightness of A increases.
I think the brightness of B will increase too, as the current passing in its branch will increase.

I am not sure about my answer, what's your opinion?

 

[cnh1995]

I agree with your answer.

 

[Asmaa Mohammad]

I agree with your answer.

I have just found that my book provides the answer, it is: brightness of bulb A decreases and the brightness of bulb B doesn't change, but there is no explanation.

 

[cnh1995]

I have just found that my book provides the answer, it is: brightness of bulb A decreases and the brightness of bulb B doesn't change, but there is no explanation.

That's wrong.
Maybe this is the answer to some other similar question and the book just printed it at the wrong place.