Should the oven heating coil stay on the whol time you are baking?
Most likely No. Most electric ovens heat to certain temperatures by turning the heating element on and off with a thermostat, much like your home thermostat will keep your house hot. This is referred to as a 'Duty Cycle'. Basically, the element may come 'on' and start glowing as it heats. Once the inside of the oven reaches the desired temperature, it may turn off and cool as much as 5-15 degrees then cycle on again.