FAA Aviation Mechanic General (AMG)Fundamentals of Electricity and ElectronicsMedium
A technician wants to reduce the resistance of a copper conductor without changing its material or length. Which modification will achieve this?
- ADecrease the cross-sectional area of the wire
- BIncrease the operating temperature of the wire
- CIncrease the cross-sectional area of the wire
- DCoil the wire into a tighter loop
Show answer & explanationAnswer & explanation
Correct answer: C. Increase the cross-sectional area of the wire
Resistance is inversely proportional to cross-sectional area; increasing the wire's diameter provides more room for electron flow, reducing resistance.
Why the other options are wrong
- A. Decreasing area increases resistance, the opposite effect.
- B. For most conductors, increasing temperature increases resistance.
- D. Coiling affects inductance, not resistance directly.
Factors Affecting Resistance
A conductor's resistance depends on its length, cross-sectional area, material type, and temperature.
- Resistance increases with length
- Resistance decreases with larger cross-sectional area
- Different materials have different resistivity
- Most conductors' resistance increases with temperature
Memory trick: LAMT: Length, Area, Material, Temperature — think of a garden hose.