Final answer:
Different wattage bulbs transfer electric energy into light and heat at different rates because they have varying levels of electric current and resistance. A higher wattage bulb, like a 60-W, emits brighter and warmer light due to the greater conversion of electrical energy, compared to a 25-W bulb. CFL bulbs can match the brightness at much lower power usage.
Step-by-step explanation:
Lightbulbs of different wattages transfer electric energy into light energy and thermal energy at different rates because they draw different amounts of electric current and operate at different levels of efficiency. When electricity flows through the filament of a lightbulb, it encounters resistance which causes it to heat up and emit light. The amount of electric power, in watts, that a bulb consumes depends on the amount of current flowing through it and the voltage across it, as described by the formula Power (P) = Voltage (V) × Current (I).
A 25-W bulb, compared to a 60-W bulb, will draw less current or have higher resistance, thus emitting less light and heat. Meanwhile, the 60-W bulb, with its higher power rating, will generate more heat and provide higher light intensity. The reason a 60-W bulb appears brighter and warmer is due to more electrical energy being converted into light and thermal energy.
In terms of energy efficiency, not all lightbulbs are equal. For example, a compact fluorescent light (CFL) bulb can emit the same light intensity as a 60-W incandescent bulb but will use only 1/4 to 1/10 the input power. This is due to the different mechanisms by which various types of bulbs produce light and the varying efficiencies of these processes.