Question

A fused bulb does not glow. Why?

Answer 1

Hint Start by thinking about the construction of the bulb and which part of the bulb’s structure makes the bulb glow. And how does a bulb get fused and what happens when it does get fused?

Complete step by step answer
As explained in the hint section of the question, we will start by checking the construction of the bulb and thinking about which part of the bulb makes it glow.
A diagram of the bulb is shown below:

As we can see, there is a filament in the center of the bulb, and this is the part of the structure of the bulb which is responsible for generating light and making the bulb glow. It is also an element of the circuit of the bulb which actually generates heat in the coil filament of usually tungsten which generates heat along-with light. That is why when you touch a glowing bulb, the bulb is hot if it has been glowing for quite some time.
A bulb can get fused in multiple ways due to multiple reasons, but the most common way is when the coil filament of the bulb breaks. Since it is an integral part of the circuit of the bulb, if it breaks, the circuit gets broken and no current then flows through the circuit. Also, since it is the light generating part of the bulb’s structure, if it breaks, there will be no light generated as it was this party's responsibility alone.

Note Many students answer the question only as “Since the circuit is broken, the bulb does not glow.” But to get full marks, you need to explain the construction of the bulb, mention the part which is responsible for generating light and heat and what happens when the bulb gets fused.