Examkin

Soru

Zorluk: KolayResistance and Resistivity

An electrical technician wants to reduce the electrical resistance of a standard copper wire run without changing the metal type or operating temperature. Which of the following modifications will decrease the resistance of the wire?

  1. A
    Increasing the total length of the wire
  2. Increasing the cross-sectional area of the wireCevap
  3. C
    Operating the wire at a significantly elevated temperature
  4. D
    Selecting a wire with a smaller circular diameter

Cevap

Increasing the cross-sectional area of the wire decreases its electrical resistance.
Electrical resistance in a conductor is inversely proportional to its cross-sectional area (R=ρLAR = \rho \frac{L}{A}). Increasing the thickness or cross-sectional area provides more conductive pathways for free electrons, thereby lowering the total resistance.

Adım Adım Çözüm

1
Recall the fundamental physical relationship between conductor dimensions and electrical resistance
R=ρLAR = \rho \frac{L}{A}, where RR is resistance, ρ\rho is material resistivity, LL is conductor length, and AA is cross-sectional area
This formula defines how physical geometry directly influences opposition to electron flow.
2
Analyze how changing the cross-sectional area (AA) impacts resistance (RR)
Because cross-sectional area (AA) is in the denominator, resistance is inversely proportional to area (R∝1AR \propto \frac{1}{A})
Increasing the area (AA) reduces the calculated resistance (RR), allowing electrons to flow more easily.

Anahtar Kavram

Physical factors governing conductor resistance
Tahmini Süre:45s
Bu soruyu puanla

Konular

Resistance and Resistivity

Bu konudan daha fazla soru