All High School Physics Resources
Example Questions
Example Question #7 : Electric Circuits
An electrical circuit has a current of and of resistance. What is the voltage?
For this problem use Ohm's law:
We are given the resistance and the current, allowing us to solve for the voltage.
Example Question #11 : Electricity And Magnetism
A circuit has a current, , a voltage, , and a resistance, . If the voltage remains constant, but the current is doubled (), what must the new resistance be?
There is insufficient information to solve
To solve this problem, use Ohm's law:
Since we are doubling the current, but the voltage is remaining the same, we can set our old and new equations equal to each other.
We know that the second current is equal to twice the first current.
Use this equation to substitute current into the first equation.
The initial current now cancels out from both sides.
Divide both sides by two to isolate the final resistance variable.
Example Question #11 : Electricity And Magnetism
Ohm's Law describes the relationship between which variables?
Power, resistivity, electromotive force
Voltage, current, resistance
Voltage, electric field, power
Resistance, power, electromotive force
Electric field, current, power
Voltage, current, resistance
Ohm's law can be written as:
It demonstrates that voltage is equal to the product of current and resistance within an electric circuit.
Example Question #12 : Use Ohm's Law
The current in a circuit is and the voltage is . What is the resistance?
Ohm's law says . Plug in our given values to solve.
Example Question #13 : Electricity And Magnetism
What is the current of a circuit with a voltage of and a total resistance of ?
For this problem, use Ohm's law: . In this equation is the voltage, is the current, and is the resistance.
We can re-arrange the equation to solve specifically for .
Plug in the given values for voltage and resistance to solve for the current.
Example Question #14 : Electricity And Magnetism
What is the resistance in a circuit with a voltage of and a current of ?
For this problem, use Ohm's law: . In this equation is the voltage, is the current, and is the resistance.
We can re-arrange the equation to solve specifically for .
Plug in the given values for voltage and current and solve for resistance.
Example Question #12 : Electricity And Magnetism
What is the voltage of a circuit with of current and of resistance?
For this problem, use Ohm's law: . In this equation is the voltage, is the current, and is the resistance.
Plug in the given values and solve for the voltage.
Example Question #13 : Electricity And Magnetism
Ohm's Law describes the relationship between which variables?
Voltage, electric field, power
Resistance, power, electromotive force
Voltage, current, resistance
Power, resistivity, electromotive force
Electric field, current, power
Voltage, current, resistance
Ohm's law can be written as:
It demonstrates that voltage is equal to the product of current and resistance within an electric circuit.
Example Question #17 : Electricity And Magnetism
A circuit has a current, , a voltage, , and a resistance, . If the voltage remains constant, but the current is doubled (), what must the new resistance be?
There is insufficient information to solve
To solve this problem, use Ohm's law:
Since we are doubling the current, but the voltage is remaining the same, we can set our old and new equations equal to each other.
We know that the second current is equal to twice the first current.
Use this equation to substitute current into the first equation.
The initial current now cancels out from both sides.
Divide both sides by two to isolate the final resistance variable.
Example Question #12 : Electricity And Magnetism
What is the power of a circuit with a current of and a resistance of ?
The standard equation for power is:
We are given only current and reistance, meaning we must manipulate this equation so that only those variables are present. To do this, we can substitute Ohm's law for voltage.
Now we have an equation for power that uses only current and resistance. Plug in the values given in the question to find the final answer.