Charge

Definition

Charge is a fundamental property of matter that is the source of all electrical phenomena. It is the basic unit of electrical charge that can be either positive or negative and is responsible for the creation of electric fields and the flow of electric current.

5 Must Know Facts For Your Next Test

1. Charge can be either positive or negative, and it is quantized, meaning it comes in discrete amounts.
2. The SI unit of charge is the coulomb (C), and it is defined as the amount of charge that passes through a cross-section of a conductor carrying a current of one ampere for one second.
3. Charge is conserved, meaning that the total charge in a closed system remains constant over time.
4. The electric field around a charged particle or object is proportional to the charge and inversely proportional to the square of the distance from the charge.
5. Capacitors store electric charge, and the amount of charge they can store is determined by their capacitance and the voltage applied across them.

Review Questions

• Explain how the concept of charge is related to the electric field in the context of 18.4 Electric Field: Concept of a Field Revisited.
  • Charge is the fundamental property that creates electric fields. According to 18.4, an electric field is the region surrounding a charged particle or object where a force would be exerted on another charged particle or object. The strength of the electric field is directly proportional to the charge of the object creating the field and inversely proportional to the square of the distance from the charge. Therefore, the concept of charge is central to understanding the creation and properties of electric fields, as described in the 18.4 Electric Field: Concept of a Field Revisited topic.
• Describe how the concept of charge relates to the behavior of capacitors in series and parallel circuits, as discussed in 19.6 Capacitors in Series and Parallel.
  • In the context of 19.6 Capacitors in Series and Parallel, the concept of charge is crucial for understanding how capacitors store and release electric charge. Capacitance, which is the measure of a capacitor's ability to store charge, is directly related to the amount of charge a capacitor can hold. The total charge stored in a capacitor is equal to its capacitance multiplied by the voltage applied across it. Additionally, the way capacitors are connected in series or parallel affects the overall charge storage and distribution in a circuit, as described in the 19.6 topic.
• Analyze how the concept of charge is fundamental to the behavior of DC circuits containing resistors and capacitors, as discussed in 21.6 DC Circuits Containing Resistors and Capacitors.
  • In the 21.6 topic, the concept of charge is essential for understanding the behavior of DC circuits containing resistors and capacitors. Charge is the driving force behind the flow of electric current, which is measured in amperes (A) and is the rate of charge flow. The way charge is stored and released by capacitors, and the way it flows through resistors, determines the voltage, current, and energy relationships in these circuits. Additionally, the time-dependent behavior of charge in RC circuits, such as charging and discharging, is a key concept covered in 21.6 DC Circuits Containing Resistors and Capacitors.

Related terms

Electric Field: An electric field is the region surrounding a charged particle or object where a force would be exerted on another charged particle or object.

Capacitance: Capacitance is the ability of a capacitor to store an electric charge, and it is measured in farads (F).

Current: Electric current is the flow of electric charge through a conductive material, such as a wire, and is measured in amperes (A).