Welcome to 6D 2010 ! Enjoy!=D

Let me try to rephrase Colin's and Zaw's questions.

If the voltage of the battery is higher than the bulb, the bulb will fuse.

The task that I had asked you to try is to find out what is the voltage of the bulb. ( ** Zaw suggested that we can test it out by adding the number of batteries until the bulb fuses. )

So let's assume that the maximum number of batteries (1.5v) that could be added to the circuit is 5.

What would happen if we added another bulb instead? Can the circuit now allows a total of 10 ( 1.5v) batteries?

I hope it is clearer now. I would strongly encourage all of you to participate in this discussion. Learning is really about discovering new information on your own. Only then you will learn and remember better.