AP Physics 2 : Ohm's Law

Study concepts, example questions & explanations for AP Physics 2

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Example Questions

Example Question #171 :Electricity And Magnetism

Three parallel resistors

What is the current flowing through?

Possible Answers:

Impossible to determine

None of these

Correct answer:

Explanation:

,, andare in parallel, so we add them by using:

We find that

,, andare in series. So we use:

First, we need to find the total current of the circuit, we simply use:

Because,andare in parallel,

Also, the voltage drop must be the same across all three

Using

Using algebraic subsitution we get:

Solving for

Example Question #172 :Electricity And Magnetism

Three parallel resistors

What is the current flowing through?

Possible Answers:

None of these

Correct answer:

Explanation:

,, andare in parallel, so we add them by using:

We find that

,, andare in series. So we use:

We will then find the total current of the circuit. This will also be the current ofbecause this resistor is not in parallel with any others.

Example Question #173 :Electricity And Magnetism

Three parallel resistors

What is the current flowing through?

Possible Answers:

Impossible to determine

None of these

Correct answer:

Explanation:

,, andare in parallel, so we add them by using:

We find that

,, andare in series. So we use:

First, we need to find the total current of the circuit, we simply use:

Because,andare in parallel,

Also, the voltage drop must be the same across all three

Using

Using algebraic subsitution we get:

Solving for

Example Question #11 :Circuits

Three parallel resistors

What is the voltage drop across?

Possible Answers:

None of these

Correct answer:

Explanation:

,, andare in parallel, so we add them by using:

We find that

,, andare in series. So we use:

We will then determine the total current of the circuit.

Once again, using

Whereis the resistance of the resistor in question, we get

Example Question #12 :Circuits

Three parallel resistors

What is the voltage drop across?

Possible Answers:

None of these

Correct answer:

Explanation:

,, andare in parallel, so we add them by using:

We find that

,, andare in series. So we use:

First, we need to find the total current of the circuit, we simply use:

Because,andare in parallel,

Also, the voltage drop must be the same across all three

Using

Using algebraic subsitution we get:

Solving for

Using

例子问题# 13:Circuits

Parallel circuit 1 jpeg

The current throughis,has a resistance of. Determine the voltage of the battery.

Possible Answers:

Correct answer:

Explanation:

Due to the "loop rule", the voltage increase in the battery will need to be equal to the voltage drop in the resistor.

Use Ohm's law:

Combine equations:

Plug in values:

Example Question #14 :Circuits

Parallel circuit 1 jpeg

If the battery has a voltage of, andhas a resistance of, determine the current through.

Possible Answers:

Correct answer:

Explanation:

Due to the "loop rule", the voltage increase in the battery will need to be equal to the voltage drop in the resistor.

Use Ohm's law:

Combine equations:

Plug in values:

Example Question #15 :Circuits

Abattery is placed in series with fiveresistors. Find the total resistance.

Possible Answers:

Correct answer:

Explanation:

In series, resistance adds conventionally.

Example Question #16 :Circuits

Abattery is placed in series with fiveresistors. Find the voltage drop across each resistor.

Possible Answers:

Correct answer:

Explanation:

In series, resistance adds conventionally.

Using Ohm's law for total current:

Now use Ohm's law for an individual resistor:

Example Question #17 :Circuits

Abattery is placed in series with fiveresistors. Find the current.

Possible Answers:

Correct answer:

Explanation:

In series, resistance adds conventionally.

Using

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