Video Transcript
The diagram shows four circuits. Which one shows a fuse and a filament lamp connected to a cell in parallel?
In this question, we are given four circuits, and we are asked to find the circuit which shows a fuse and a filament lamp connected to a cell in parallel. We will begin by identifying each of the components in the circuit diagrams by their circuit symbols. We have an ammeter, a cell, a filament lamp, a fuse, a light-emitting diode, or LED, a resistor, and a voltmeter.
Now that we know what each of the components looks like in a circuit diagram, we can begin to eliminate some of the circuits. In circuit (C), we can see that it contains a cell, a filament lamp, and a resistor. But this circuit does not contain a fuse, so (C) is an incorrect circuit. In circuit (D), we can see that it contains a cell, a fuse, and an LED. But this circuit does not contain a filament lamp, so (D) is an incorrect circuit. This leaves circuits (A) and (B). In circuit (A), we have an ammeter, a cell, a filament lamp, a fuse, and a voltmeter. We can see that the voltmeter is connected in parallel with the filament lamp. However, the fuse and filament lamp are connected in series instead of in parallel. So circuit (A) is also incorrect.
This leaves circuit (B). In circuit (B), we have a cell, a filament lamp, and a fuse. The path between the two terminals of the cell splits into two paths at point 𝐴. One path contains the filament lamp, and the other path contains the fuse. And then the paths join together again at point 𝐵. So the filament lamp and the fuse are connected in parallel. And therefore, circuit (B) is the correct circuit which shows a fuse and a filament lamp connected to a cell in parallel.
