2018 #2 Free Response Question - AP Physics 1 - Exam Solution

The video tutorial covers question #2 from the 2018 AP Physics exam, focusing on determining the resistivity of conductive dough cylinders. It explains how to graph resistance and length to find resistivity, emphasizing the importance of labeling axes and using a straight edge for accuracy. The tutorial also discusses how the shape of the dough does not affect resistivity and outlines an experimental procedure to test if resistivity changes with temperature.

What is the primary purpose of the experiment involving conductive dough cylinders?

• To find the density of the dough

• To measure the temperature of the dough

• To determine the resistivity of the dough

• To calculate the volume of the dough

Which quantities should be plotted on the graph to find the resistivity of the dough?

• Length and width

• Resistance and length

• Resistance times area and length

• Area and volume

What is the unit for the product of resistance and cross-sectional area?

• Ohm meters

• Ohms

• Meters

• Ohm meters squared

Why is it important to label axes with units when plotting the graph?

• To follow the teacher's instructions

• To use more space on the paper

• To ensure clarity and accuracy in data interpretation

• To make the graph look neat

What does the slope of the best fit line on the graph represent?

• The resistivity of the dough

• The volume of the dough

• The length of the dough

• The temperature of the dough

How does changing the shape of the dough affect its resistivity?

• It increases the resistivity

• It does not affect the resistivity

• It makes the resistivity unpredictable

• It decreases the resistivity

What is the main factor being tested in the experiment designed in Part C?

• The effect of color on resistivity

• The effect of temperature on resistivity

• The effect of shape on resistivity

• The effect of mass on resistivity

What should be kept constant in the experiment to test temperature dependence?

• The shape of the dough

• The length of the dough

• The electric potential difference

• The color of the dough

What happens to the current if the resistivity of the dough changes with temperature?

• The current remains constant

• The current increases

• The current fluctuates randomly

• The current decreases

Why might a diagram not be necessary for the experimental setup in Part C?

• Diagrams are too complex

• The description is detailed enough

• Diagrams are not allowed

• The experiment is too simple