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What is the difference between resistivity and resistance?
Resistivity: Intrinsic property of a material, independent of shape and size. Resistance: Depends on the material's resistivity, length, and cross-sectional area.
Compare conductors and insulators in terms of resistivity.
Conductors: Low resistivity, allowing easy current flow. Insulators: High resistivity, hindering current flow.
What is the effect of increasing temperature on resistivity (generally)?
Generally, as temperature increases, resistivity also increases.
What is the effect of increasing temperature on resistance (generally)?
Generally, as temperature increases, resistance also increases.
What is the effect of increasing the length of a wire on its resistance?
Increasing the length of a wire increases its resistance.
What is the effect of increasing the cross-sectional area of a wire on its resistance?
Increasing the cross-sectional area of a wire decreases its resistance.
What is the effect of changing the shape of a material on its resistivity?
Changing the shape of a material does not affect its resistivity.
What is the effect of decreasing current with constant voltage on resistance?
Since V is constant and I decreases, the resistance R must increase (R = V/I).
What are the steps to determine resistivity experimentally?
- Mold conductive dough into cylinders of varying lengths (L) and cross-sectional areas (A). 2. Measure the resistance (R) by applying a potential difference ((Delta V)). 3. Calculate L/A for each cylinder. 4. Plot R vs. L/A. 5. The slope of the graph will give the resistivity (( ho)).
How do you determine if resistivity changes with temperature?
- Measure the resistance of the dough at different temperatures. 2. Vary the temperature using an ice bath or heat source. 3. Keep the length and cross-sectional area constant. 4. Record the temperature and corresponding resistance. 5. Plot resistance against temperature to analyze the relationship.
How to calculate resistivity ()?
- Measure the resistance (R) of the material. 2. Determine the cross-sectional area (A) of the material. 3. Measure the length (L) of the material. 4. Use the formula: