All AP Physics 1 Resources
Example Questions
Example Question #1 : Ohm's Law
Consider the circuit:
If each resistor has a value of , how much current is flowing through the circuit?
First we need to calculate the equivalent resistance of the circuit using the following expression for condensing parallel resistors:
Now we can use Ohm's law to calculate the current flowing through the circuit:
Example Question #2 : Ohm's Law
A light bulb requires 60 W to function properly. If it is connected to a powersupply of 120 A and functions properly, then what is the resitance of the light bulb?
First, identify the given information:
Two equations are required for this problem:
1.) Ohm's law,
2.) Electrical power
Using the equation for electrical power, we can rearrange to solve for :
At this point, we can substitute in the known values and determine the voltage:
Ohm's law can then be rearranged to solve for the resistence of the light bulb:
The known voltage value then can be substituted into Ohm's law to determine the resistance of the light bulb:
Example Question #1 : Ohm's Law
What is the resistance of a resistor if the current going through it is and the voltage across it it is ?
Use Ohm's law.
Plug in known values and solve for resistance.
Example Question #1 : Ohm's Law
What is the voltage across a resistor with a resistance of that has a current of going through it?
Use Ohm's Law.
Example Question #1 : Ohm's Law
What is the current through a resistor if the resistor has a resistance of and the voltage across the resistor is ?
Use Ohm's law.
Example Question #1 : Ohm's Law
If the current through a resistor is , what is the voltage across the resistor?
UseOhm's law.
Plug in known values and solve.
Example Question #1 : Ohm's Law
The voltage measured from a point between and to the ground is
What is the resistance of ?
Begin by finding the total resistance in the circuit.
Now note that the voltage identified in the problem is the same as the voltage drop across the second resistor:
Now, since and combine to form the total resistance:
Example Question #2 : Circuits
, and the voltage measured from a point between and to the ground is
In the circuit above, what is the resistance of ?
Begin by finding the total resistance in the circuit.
Now note that the voltage identified in the problem is the same as the voltage drop across the second resistor:
Example Question #3 : Ohm's Law
is composted of two resistors in parallel, and
is a single resistor.
In the circuit above, what is the current?
To find the current, first find the total resistance of the circuit. Begin by simplifying , the two resistors in parallel as follows:
Since and are in series, their combined resistance is:
Use Ohm's law to find the current.
Example Question #1 : Ohm's Law
A resistor with a resistance of has a current flowing through it of 5A. What is the potential drop across the resistor?
Ohm's law states that the potential drop across a resistor is equal to the product of the current flowing through the resistor and the resistance of the resistor:
We were given the current, I, and the resistance, R, so we simply multiply the two together to get our final answer.
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