Which one of the given fuses is bigger?
Right Answer is:
The main difference between the DC Fuses and AC Fuses is the size of the fuse. In a DC circuit, when the current exceeds the limit, the metallic wire in the fuse melts and disconnects the rest of the circuit from the power supply. When the fuse blows due to over-current, an arc can form, re-energizing faulty load.
Since DC is the constant value and is always above 0V, there is a chance of an electric arc between the melted wires, which will be difficult to avoid and turn off. Hence, usually, the electrodes of the DC Fuses are placed at a larger distance when compared to the AC Fuses.
This will minimize the chance of arc and since the distance between the electrodes is increased, the size of the DC Fuses is comparatively large.
We know that AC current (and voltage) oscillates 50 or 60 times per second and in this, the amplitude of the signal varies from minimum to maximum. At one point of this oscillations, the AC Voltage touches the 0V and hence the arc between the melted electrodes can be easily terminated.
As a result, the size of the AC Fuses can be much smaller when compared to the size of DC Fuses.