Will the Bulb Connected in This Strange Circuit Glow? And What is the Current in Ammeter?

Electrical Technology

Will the Bulb Glow Connected in this Strange Circuit? Also, What is the Ammeter Readings?

Basic Electrical Engineering Interview Question Series: A bulb is connected in a strange circuit in series with an ampere meter as shown in fig below. Also, what will be the current in ammeter?

Short Answer: Bulb will not glow with zero ampere current in ampere meter due to open circuit.

Explanatory Answer:

At all, this circuit does not make sense i,e, it is an open circuit, so light bulb will not glow and the current in ampere meter is Zero (0).

If we rearrange the circuit above, it will become like the following one which clearly shows the incoming Line (Live or Phase) wire is connected to the light bulb and ammeter and then connected back to the line instead of neutral. In other words, the circuit is not completed as there is no Neutral connected to the bulb or ammeter but only live wire connected back to itself. This way, there is no proper path available for current flow in the circuit.

For this reason, there will be no deflection in ampere meter i.e. it will show zero reading due to no current. Hence bulb will not be able to glow at all.

As a basic, there must be a proper connection of both phase and neutral wire to the load (light bulb in our case). The neutral is not connected to the load, this way, there is no current flowing in the circuit as it is an open circuit.

These basic and confusing questions are asked in our page inbox by followers. If you got something like this, don’t hesitate to ask in the page inbox or in the comment box below. We will try our best to clear the basic concept with explanation.

Also read more basic Electrical Technology Question and Answers like this: