Browse By Unit
3 min readโขjune 18, 2024
Peter Apps
Peter Apps
As of 2021, College Board only tests Units 1-7 on the AP Physics 1 exam. This page's content will not be tested on the exam, but we kept it online for you all as a resource.
Electric charge is a property of an object or a system that affects its interactions with other objects or systems containing the charge.
The electric charge is conserved. The net charge of a system is equal to the sum of the charges of all the objects in the system.
A circuit is aย closed loop of electrical current. If the loop is open or doesnโt allow the current to return to its starting position, electricity will not flow through the circuit and any devices on that partial loop will not work. Common ways of breaking a circuit include switches or blow / removed light bulbs.
Review: Remember in Unit 8, the charge is conserved. This means that throughout a given circuit, the total amount of charge must be kept the same. Chargeย CANNOT be โUsed Upโ in a circuit.
Besides Current, there are two other commonly used terms for describing circuits. They are Voltage and Resistance. In addition, youโll see the electrical energy and power mentioned occasionally as well.
Voltage is the amount of energy each electron (or other charge carriers) is given as it travels through the circuit. The source of voltage for a circuit is usually a battery of some type. As the electrons travel throughout the circuit, they transfer their energy to the device (light bulb, motor, etc) and reduce their voltage accordingly. This is referred to as a voltage drop and will be important as we analyze circuits later in this unit.
Resistance is the opposition to electrical current. It is often related to the characteristics of the conductor (more on this in 9.2). To use the water analogy, resistance is similar to a kink or twist in a hose. It reduces the flow of water outwards. With electrical circuits, resistors are added to the circuit to reduce the current to the desired value. Often these resistances convert the energy of the circuit into heat.
For an โidealโ resistor, the current, voltage and resistance can be calculated using the equation:
<< Hide Menu
3 min readโขjune 18, 2024
Peter Apps
Peter Apps
As of 2021, College Board only tests Units 1-7 on the AP Physics 1 exam. This page's content will not be tested on the exam, but we kept it online for you all as a resource.
Electric charge is a property of an object or a system that affects its interactions with other objects or systems containing the charge.
The electric charge is conserved. The net charge of a system is equal to the sum of the charges of all the objects in the system.
A circuit is aย closed loop of electrical current. If the loop is open or doesnโt allow the current to return to its starting position, electricity will not flow through the circuit and any devices on that partial loop will not work. Common ways of breaking a circuit include switches or blow / removed light bulbs.
Review: Remember in Unit 8, the charge is conserved. This means that throughout a given circuit, the total amount of charge must be kept the same. Chargeย CANNOT be โUsed Upโ in a circuit.
Besides Current, there are two other commonly used terms for describing circuits. They are Voltage and Resistance. In addition, youโll see the electrical energy and power mentioned occasionally as well.
Voltage is the amount of energy each electron (or other charge carriers) is given as it travels through the circuit. The source of voltage for a circuit is usually a battery of some type. As the electrons travel throughout the circuit, they transfer their energy to the device (light bulb, motor, etc) and reduce their voltage accordingly. This is referred to as a voltage drop and will be important as we analyze circuits later in this unit.
Resistance is the opposition to electrical current. It is often related to the characteristics of the conductor (more on this in 9.2). To use the water analogy, resistance is similar to a kink or twist in a hose. It reduces the flow of water outwards. With electrical circuits, resistors are added to the circuit to reduce the current to the desired value. Often these resistances convert the energy of the circuit into heat.
For an โidealโ resistor, the current, voltage and resistance can be calculated using the equation:
ยฉ 2024 Fiveable Inc. All rights reserved.