Why does the intensity of the torch light decrease with time?
a) The battery provides energy. This energy is led to the lamp by wires where it dissolves. The dissolution becomes visible as light.
b) Electrons, in which energy is stored, flow from the battery to the light bulb. Then the electrons leave the light bulb, so their energy becomes visible as glowing.
c) Chemical energy is stored in the battery. This energy flows to the light bulb through wires and there it is used up. As soon as the energy is used up, the power of the lamp decreases.
d) Energy is stored in the battery in the form of chemical compounds. As long as there is a potential for chemical reactions, this energy is transformed into light and thermal energy by the glowing of the light bulb.
