Question

A battery lights a bulb. Describe the energy changes involved in the process.

Answer 1

Energy Changes When a Battery Lights a Bulb 

1. Initial Energy

A battery stores chemical energy in the form of potential energy of the chemicals inside it.

2. Energy Conversion Process

1. Chemical Energy → Electrical Energy: When the circuit is completed, chemical reactions in the battery release electrons, producing an electric current. 
   \(\text{Chemical energy (battery)} \rightarrow \text{Electrical energy (current)}\)
2. Electrical Energy → Heat and Light Energy: The electrical energy flows through the filament of the bulb. The resistance of the filament causes it to heat up and glow, producing light and heat. 
   \(\text{Electrical energy} \rightarrow \text{Light energy + Heat energy}\)

3. Summary of Energy Transformation

The complete energy transformation can be written as:

\( \text{Chemical energy (battery)} \rightarrow \text{Electrical energy (current)} \rightarrow \text{Light energy + Heat energy (bulb)} \)

4. Explanation

- The battery provides the source of energy. 
- Electrical energy is transferred through wires to the bulb. 
- The bulb filament resists the flow of current, converting electrical energy into light and heat. 
- This process demonstrates the law of conservation of energy, where energy is not lost but changes form.