On an electric stove, the size of the flame doesn't change because there is no visible flame like you would see on a gas stove. Instead, electric stoves use electric coils or a smooth glass-ceramic surface to generate heat.
When you adjust the heat setting on an electric stove higher than what is needed to boil water, the electric coils or heating elements will indeed get hotter, and the surface temperature of the stove will increase. However, this doesn't create a visible flame like on a gas stove.
The effect of turning the heat higher than necessary can lead to several outcomes:
Faster Boiling: If you increase the heat above the minimum required to boil water, the water will reach its boiling point faster.
Wastage of Energy: Running the stove at a higher heat setting than necessary will consume more electricity than needed. It's best to set the stove to the minimum required heat for the task at hand to save energy.
Risk of Overcooking: If you're cooking something sensitive to high heat, such as sauces or delicate foods, keeping the heat too high can risk overcooking or burning them.
Difficulty in Controlling Temperature: Higher heat settings may make it more challenging to control the temperature precisely, leading to potential issues while cooking.
For most cooking tasks on an electric stove, you can start with medium heat and adjust as needed. Once water reaches a boiling point, you can lower the heat to a simmer or the appropriate level for the specific dish you're preparing. It's generally a good idea to keep the heat at a level where the food cooks evenly and doesn't scorch or burn.