I understand that voltage can exist without current so what I want to ask is will there be a potential difference across the bulb(situated after the diode) when a batteries supplied energy through a reverse biased diode? Current is "blocked" when the voltage on anode is lower than on cathode, so does it mean 0V or >0v is present on the anode side? Thanks.
1 Answer
Voltage can exist without a current, but that voltage must be caused by a static charge. If you have a wire (such as in a bulb), which is a good conductor, any charge differential from one side to the other will be very rapidly resolved (on the order of picoseconds).
Since the bulb is a wire, it will not have a static charge across its leads for any meaningful period of time. So, in this situation, the voltage across the bulb will be zero.
(Well, almost zero. When you get further into electrical engineering, you will learn that there is a very small leakage current which flows through a reverse-biased diode. This means there will be some voltage across the bulb. However, it will be so small that you will need high precision equipment to measure it)