5.2 Resistivity

• What is resistivity an intrinsic property of?

  Material
• What is the formula to calculate resistivity (\(\rho\))?

  $\rho =$$\frac{RA}{L}$
• Resistance is directly proportional to the resistivity of the material.


  True
• What determines the inherent resistivity of a material?

  Atomic structure
• Higher temperatures increase resistivity because thermal energy causes greater movement of atoms
• What is resistivity an intrinsic property of a material?

  Resistance to electric current
• Resistance is directly proportional to resistivity and length.


  True
• Adding impurities to a material disrupts the atomic lattice, increasing resistivity.


  True
• What is resistivity defined as?

  Resistance to electric current
• What is the range of resistivity for glass?

  $10^{10} - 10^{14}$ Ω·m
• Insulators like glass and rubber have high resistivity.


  True
• Match the variable in the resistivity formula with its unit:

  Length ↔️ m

  Area ↔️ $m^{2}$

  Resistivity ↔️ $\Omega \cdot m$
• The resistivity of copper is $1.7 \times 10^{ - 8} \, \Omega \cdot m$ in the example problem.


  True
• What are the units of length in the resistivity formula?

  Meters
• Resistivity is an intrinsic property of a material that quantifies how much it resists the flow of electric current
• Match the material with its approximate resistivity value:

  Copper ↔️ $1.7 \times 10^{ - 8} \Omega \cdot m$

  Aluminium ↔️ $2.8 \times 10^{ - 8} \Omega \cdot m$

  Steel ↔️ $10 \times 10^{ - 8} \Omega \cdot m$

  Glass ↔️ $10^{10} - 10^{14} \Omega \cdot m$
• What is the relationship between resistance and cross-sectional area?

  Inversely proportional
• Impurities in a material increase resistivity by scattering electrons
• Different materials have inherent resistivity based on their atomic structure and electron configuration.


  True
• The resistivity of copper is approximately 1.7 × 10^-8
• What type of proportionality exists between resistance and cross-sectional area?

  Inverse
• How does mechanical stress affect resistivity?

  May increase or decrease it
• The resistivity of copper is approximately 1.7 × 10^-8 Ω·m.
• Rubber has a resistivity in the range of 10^13 to $10^{16}$ Ω·m.
• What is the formula for calculating resistance using resistivity?

  $R =$$\frac{\rho L}{A}$
• What is the resistance of a copper wire with a length of 50 m, a cross-sectional area of 0.5 \times 10^{-6} \, m^{2}</latex>, and a resistivity of $1.7 \times 10^{ - 8} \, \Omega \cdot m$?


  $1.7 \, \Omega$
• What is the resistance of the copper wire calculated in the example problem?

  $1.7 \, \Omega$
• What is the length value in the example problem?

  50 m
• Unlike resistance, resistivity depends on the size and shape of the object.

  False
• The cross-sectional area in the equation for resistance is measured in square meters
• Higher temperatures increase resistivity.


  True
• What is resistivity (\(\rho\)) of a material?

  Resistance to electric current
• How do impurities affect resistivity?

  Increase it
• What is the equation relating resistance, resistivity, length, and cross-sectional area?

  $R =$$\frac{\rho L}{A}$
• Higher temperatures increase resistivity due to increased thermal vibration of atoms
• What is the resistivity of copper in $\Omega \cdot m$?


  $1.7 \times 10^{ - 8}$
• Metals like copper and aluminum have low resistivity.


  True
• In the formula $R =$$\frac{\rho L}{A}$, $R$ represents resistance in Ohms.
• The resistance of the copper wire is calculated to be 1.7 Ohms.
• The resistance of the copper wire is 1.7 Ohms.


  True