Answer
The electric field through out the entire circuit changes only when the light bulb is turned on. The current then starts to flow into the bulb. This change in the current wears the bulb and may eventually be the cause of the bulb's failure.
Work Step by Step
The electric field through out the entire circuit changes only when the light bulb is turned on. The current then starts to flow into the bulb. This change in the current wears the bulb and may eventually be the cause of the bulb's failure.