3) Using ohm’s law, explain how voltage changes in relation to current, assuming that resistance remains constant.
4) As the electric current in a lightbulb is slowly increased the filament glows more and more brightly. Why does this happen?
5) Why did some of the lightbulb’s you tried burn out?
6) Why is there zero current when a lightbulb burns out?

Question

3)	Using ohm’s law, explain how voltage changes in relation to current, assuming that resistance remains constant.
4)	As the electric current in a lightbulb is slowly increased the filament glows more and more brightly. Why does this happen?
5)	Why did some of the lightbulb’s you tried burn out?   
6)	Why is there zero current when a lightbulb burns out?

anonymous · Answer

Q3 for a given resistance, increasing voltage will result in a proportionally higher current. This is because resistance is proportional to the voltage over the current (as a formula I=V/R where R is resistance, V is voltage and I is current).

Q4 as the current increases the filament gets hotter, so the energy of the photons emitted increases and their frequency increases ie the light goes from dull red to bright white.

Q5 the filament can get too hot and melt, which means the electrons can't get across the gap.

Q6 the electrons can't get across because there isn't anything to carry them in a light bulb - not even air.