Electric ovens are usually more accurate than gas ovens but oven temperatures vary widely—and not just from oven to oven. Inside your oven there are areas that are warmer than others. Oven thermometers will help to get you closer to an accurate temperature, but depending on the quality of the thermometer, readings can vary just as widely between thermometers as with ovens.
Baking a batch of pre-made biscuits that you buy in the refrigerator case can be an inexpensive way to see how accurate your oven is. Bake them at the temperature called for in the package directions. If the biscuits call for being done in 12 minutes and they are not quite done, increase the temperature by 25°F for a second batch. (If they are overdone, decrease the temperature by 25°F.)
By baking the biscuits on a cookie sheet you can also see which ones brown earlier showing you the warmer areas of your oven.