Question
Why should a 5-ampere fuse never be replaced with a 20-ampere fuse?
Answer Options
- A) The larger fuse would be likely to blow because it is rated for higher current
- B) The power supply ripple would greatly increase
- C) Excessive current could cause a fire
- D) All these choices are correct
Correct Answer: C
Explanation
A fuse is rated to protect the weakest link in the circuit, which is usually the internal wiring or components designed to safely handle a specific maximum current (in this case, 5 amperes). If you replace a 5A fuse with a 20A fuse, the new fuse will not blow until the current reaches 20A.
By that time, the circuit’s internal wiring, which can only safely handle 5A, will have overheated significantly. This excessive current and heat can cause the wire insulation to melt, short circuits, component destruction, and ultimately, a serious fire. Always replace a fuse with one of the exact specified current rating.
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