5.2 Resistivity

Cards (49)

  • The resistivity of a material increases with higher temperature.

    True
  • Copper has a lower resistivity than aluminum.

    True
  • What happens to resistivity when impurities are added to a material?
    Increases
  • What is resistivity expressed in?
    Ohm-meters
  • Arrange the components of the resistivity formula in the correct order:
    1️⃣ Resistance (R)
    2️⃣ Resistivity (ρ)
    3️⃣ Length (L)
    4️⃣ Cross-sectional area (A)
  • The resistivity of a material is represented by the Greek letter ρ
  • Arrange the components of the resistivity formula in the correct order:
    1️⃣ Resistance (R)
    2️⃣ Resistivity (ρ)
    3️⃣ Length (L)
    4️⃣ Cross-sectional area (A)
  • The resistivity of a material increases with higher temperature
  • Materials like glass have extremely high resistivity.
    True
  • The resistivity of a material decreases with higher temperature.
    False
  • Match the material with its resistivity value:
    Copper ↔️ 1.7×10−81.7 \times 10^{ - 8}
    Aluminum ↔️ 2.8×10−82.8 \times 10^{ - 8}
    Iron ↔️ 1.0×10−71.0 \times 10^{ - 7}
    Glass ↔️ 1010−101410^{10} - 10^{14}
  • The units of resistivity are ohm-meters (Ω⋅m), which measures the opposition of a material to the flow of electric current
  • Materials with a positive temperature coefficient of resistivity include metals, while semiconductors often have a negative coefficient.
  • Resistivity decreases with temperature for all materials.
    False
  • Higher impurity levels in a material increase its resistivity.

    True
  • Match the material with its resistivity value:
    Copper ↔️ 1.7×10−81.7 \times 10^{ - 8}
    Aluminum ↔️ 2.8×10−82.8 \times 10^{ - 8}
    Glass ↔️ 1010−101410^{10} - 10^{14}
  • The effect of temperature on resistivity is that it increases
  • What does the temperature dependence of resistivity describe?
    Change in resistivity with temperature
  • Why do semiconductors often have negative temperature coefficients?
    Increased carrier concentration
  • Thermistors use semiconductors to detect temperature changes
    True
  • A copper wire with a resistance of 0.17 Ω has a higher resistivity than a nichrome wire with a resistance of 3.4 Ω
    False
  • The temperature of a material affects its resistivity.

    True
  • The resistivity of a material is affected by temperature, material composition, and impurities.

    True
  • Semiconductors have a negative temperature coefficient of resistivity because carrier concentration increases with temperature.

    True
  • Match the material with its temperature coefficient of resistivity:
    Copper ↔️ 3.9 \times 10^{ - 3}</latex>
    Silicon ↔️ −7.5×10−2- 7.5 \times 10^{ - 2}
    Germanium ↔️ −4.8×10−2- 4.8 \times 10^{ - 2}
  • What is the formula for resistivity relating resistance, length, and cross-sectional area?
    R=R =ρLA \rho \frac{L}{A}
  • What is the SI unit of resistivity?
    Ohm-meters (Ω⋅m)
  • Why does higher temperature increase resistivity?
    Atomic vibrations hinder electron flow
  • What is the temperature coefficient of resistivity denoted by?
    α\alpha
  • Match the material with its application and description:
    Copper ↔️ Electrical wiring ||| Low resistivity enables efficient power transmission
    Iron alloys ↔️ Heating elements ||| High resistivity facilitates heat generation
    Semiconductors (Silicon) ↔️ Thermistors ||| Temperature sensitivity allows precise sensing
    Insulators (Glass) ↔️ Electrical insulation ||| High resistivity prevents current leakage
  • What do sensors leverage to detect environmental changes?
    Resistivity variations
  • Match the material with its resistivity value:
    Copper ↔️ 1.7×10−81.7 \times 10^{ - 8} Ω⋅m
    Aluminum ↔️ 2.8×10−82.8 \times 10^{ - 8} Ω⋅m
    Nichrome ↔️ 1.0×10−61.0 \times 10^{ - 6} Ω⋅m
    Glass ↔️ 1010−101410^{10} - 10^{14} Ω⋅m
  • What is resistivity a material property of?
    Opposition to electric current
  • Resistivity, resistance, length, and cross-sectional area are related by the formula R
  • What are the units of resistivity?
    Ω⋅m
  • What is the resistivity of copper in Ω⋅m?
    1.7×10−81.7 \times 10^{ - 8}
  • The resistivity of a material varies depending on its material composition
  • What is the formula for resistivity?
    R=R =ρLA \rho \frac{L}{A}
  • What is the resistivity of copper in ohm-meters?
    1.7×10−81.7 \times 10^{ - 8}
  • Why does resistivity increase with temperature?
    Thermal vibrations increase collisions