All AP Physics 2 Resources
Example Questions
Example Question #61 : Circuit Properties
A resistor is made out of a material. The resistor has a cross-sectional area of  and a length of . It is found to have a resistance of . A new resistor is built that has a length of  and a cross sectional area of . Determine the resistance of the new resistor.
None of these
Using
Plugging in values
UsingÂ
Plugging in values
Example Question #66 : Circuit Properties
 identical resistors are placed in parallel. They are placed in a circuit with a  battery. If the current through the battery is , determine the resistivity of each resistor. Each resistor is  long and has a diameter of .
None of these
Since each resistor is in parallel, the voltage drop across each will be .
Since each resistor is identical, they all have the same resistance.
Using
and
It is determined that
Using
 for all three resistors
Using definition of resistivity:
Example Question #21 : Resistivity
A resistor is made out of a material. The resistor has a cross-sectional area of and a length of . It is found to have a resistance of . Determine the resistivity of the material.
None of these
Use the equation for resistivity:
Plugging in values
Example Question #231 : Electricity And Magnetism
A resistor is made out of a material. The resistor has a cross-sectional area of and a length of . It is found to have a resistance of . A new resistor is built that has a length of and a cross sectional area of . Determine the resistance of the new resistor.
None of these
Use the equation for resistivity:
Plugging in values
UsingÂ
Plugging in values
Example Question #881 : Ap Physics 2
A resistor is made out of a material. The resistor has a cross-sectional area of and a length of . It is found to have a resistance of . A new resistor is built that has a length of and a cross sectional area of . The new resistor is placed in series with a battery. Determine the current through the resistor.
None of these
Use the equation for resistivity:
Plugging in values
Rearrange the same equation and solve for resistance:
Plugging in values
Use Ohm's law to find current:
Example Question #71 : Circuits
A scientist is testing resistors made of the same material. Resistor has a cross sectional area of and a length of . Resistor has a cross sectional area of and a length of . How will the resistance of compare to that of ?
The resistance will quadruple
None of these
The resistance will double
The resistance will be cut in half
The resistance will stay the same
The resistance will be cut in half
Use the equation for resistivity to visualize the proportions:
 will stay constant as the material is the same.  doubles and  stays the same. Thus, the resistance, , will get cut in half.
Example Question #71 : Circuit Properties
A resistor is made out of a material. The resistor has a cross-sectional area of  and a length of . It is found to have a resistance of . Determine the resistivity of the material.
Using
Plugging in values
Example Question #71 : Circuits
A resistor is made out of a material. The resistor has a cross-sectional area of  and a length of . It is found to have a resistance of . A new resistor is built that has a length of  and a cross sectional area of . The new resistor is placed in series with a  battery. Determine the current through the resistor.
None of these
Using
Plugging in values
UsingÂ
Plugging in values
Using
Solving forÂ
Example Question #74 : Circuit Properties
A scientist is testing resistors made of the same material. Resistor  has a cross sectional area of  and a length of . Resistor  has a cross sectional area of  and a length of . How will the resistance of  compare to that of ?
It is impossible to determine
None of these
The resistance of  will be a quarter of that ofÂ
They will be the same
The resistance of  will be a quarter of that ofÂ
The resistance of  will be a quarter of that ofÂ
Using
 will stay constant as the material is the same.  increases by a ratio of , and  decreases by a ratio of  . Thus, the resistance, , will decrease to a quarter of it's original value.Â
Example Question #881 : Ap Physics 2
A cubic resistor is placed in a circuit. If each edge measures  long, the voltage of the battery is  and the current through the resistor is , determine the resistivity.
None of these
Determining the resistance
Using
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