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Fuse
A fuse protects a circuit by melting its element when excessive current produces enough heating to open the circuit.
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Fuse
Recommended for Class 10
Fuse
A fuse is an electrical safety device designed to interrupt a circuit when current exceeds a safe value.
It contains a fuse element that heats when current passes through it.
Because heating depends strongly on current:
**P = I²R**
an excessive current produces rapid heating.
The fuse element then melts, opening the circuit.
Fuse Rating
A fuse is selected with a current rating suitable for the appliance or circuit.
During normal operation it should carry the required current.
If a dangerous overcurrent occurs, it should disconnect the circuit.
Why Fuses Matter
Excessive current can:
overheat wires; damage equipment; * increase fire risk.
Fuse vs Circuit Breaker
A fuse melts and normally needs replacement after operation.
A circuit breaker can generally be reset after the fault has been corrected.
Fuse — Advanced
Common Mistakes
Common Mistakes
- Mistake
Mistake: Fuse connected in parallel with the appliance. Correction: A fuse is not connected in parallel with the appliance.
- Mistake
Mistake: Fuse not in the current path. Correction: It must be in the current path so that opening it disconnects the circuit.
Revision Zone
60-Second Revision
Quick cues from this topic — use them for last-minute revision.
Fuse → excessive current.
Heating → element melts.
Circuit → opens.
- Definition
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Practice
PQ
Q1. Define fuse.
PQ
Q2. Explain operation.
PQ
Q3. Explain rating.
PQ
Q4. Compare breaker.
PQ
Q5. Explain series connection.
Exam Practice
EQ
Q1. Describe fuse operation.
EQ
Q2. Explain I²R heating.
EQ
Q3. Explain fuse rating.
EQ
Q4. Compare fuse and circuit breaker.
EQ
Q5. Explain why fuse is in current path.
School-standard facts for Matric and Intermediate. Original explanations — not copied from textbooks.