1. What is the direction of charge flow when charging a capacitor? When discharging a capacitor? What is your evidence?
2. Consider a circuit with a capacitor, battery, wire, and bulb. Describe the source(s) of charge during capacitor discharging.
3. Using the analogy of the air capacitor, what do you think might be the cause of charge motion during capacitor discharging?
4. List at least five of the findings and assumptions that make up a model of the behavior of electricity.
For 1. This might help
http://www.tpub.com/neets/book2/3b.htm
1. When charging a capacitor, the direction of charge flow is from the positive terminal of the power source (such as a battery) towards the positive plate of the capacitor. During discharging, the flow of charge is in the opposite direction, from the positive plate of the capacitor towards the negative terminal of the power source.
The evidence for this can be observed by connecting a power source, such as a battery, to a capacitor in a circuit. When charging, the capacitor gradually stores charge and the voltage across it increases. The direction of current flow can be determined by using a multimeter to measure the voltage drop across different components in the circuit. Similarly, during discharging, the voltage across the capacitor decreases as the charge is released.
2. During capacitor discharging in a circuit with a capacitor, battery, wire, and bulb, the source of charge is the stored energy in the electric field of the capacitor. As the capacitor discharges, the electric field energy is converted into current flow through the wire. The battery is not a direct source of charge during discharging, but it initially provided the energy to charge the capacitor.
3. Using the analogy of an air capacitor, it can be inferred that the cause of charge motion during capacitor discharging is the release of stored energy. In the air capacitor analogy, imagine a container with compressed air inside. When the container is opened, the compressed air expands and flows out, releasing the stored energy. Similarly, in a capacitor, during discharging, the electric field energy stored in the capacitor is released as the charges move from one plate to another, leading to the flow of charge.
4. The findings and assumptions that make up a model of the behavior of electricity include:
- Electric charges exist and can be positive or negative.
- Like charges repel each other, while opposite charges attract.
- Current is the flow of electric charge and is measured in Amperes (A).
- Voltage is the electric potential difference between two points and is measured in Volts (V).
- Conductors allow the flow of electric charge, while insulators impede the flow.
- Ohm's Law relates the current, voltage, and resistance in a circuit: V = IR.
- Kirchhoff's laws govern the behavior of currents and voltages in a circuit.
- Capacitors store electrical energy in an electric field between two conductive plates.
- Inductors store electrical energy in a magnetic field generated by a current.
- Resistors impede the flow of electric current and dissipate electrical energy as heat.
1. When charging a capacitor, the direction of charge flow is from the positive terminal of the power source to one plate of the capacitor, while an equal amount of charge flows from the other plate of the capacitor to the negative terminal of the power source. This occurs because the power source creates a potential difference across the capacitor, causing the charges to accumulate on the plates. This process is commonly referred to as "charging."
During discharge, the direction of charge flow is reversed. The charges stored on the plates of the capacitor now flow back towards the opposite terminal of the power source. The potential difference across the capacitor gradually decreases as the charges are released, which causes the current to flow in the opposite direction compared to charging. This process is known as "discharging."
The evidence for charge flow direction during capacitor charging and discharging can be obtained through experimental observations. By connecting a power source, particularly a direct current (DC) source, to a capacitor within a circuit and observing the flow of current, one can determine the direction of charge flow during both charging and discharging.
2. In a circuit with a capacitor, battery, wire, and bulb, the source of charge during capacitor discharging is primarily the stored charges on the plates of the capacitor. When the capacitor is fully charged, it contains a certain amount of stored electric potential energy. When the circuit is completed by turning on the switch, the energy stored in the capacitor is gradually released and powers the bulb. This release of energy from the capacitor causes the charges to flow through the wire, creating an electric current that illuminates the bulb.
3. The analogy of the air capacitor can help us understand the possible cause of charge motion during capacitor discharging. In an air capacitor, the electric charges are separated by a layer of insulating air. When the air capacitor is discharged, the charges are allowed to move towards each other, causing a flow of electric current.
Similarly, during capacitor discharging in an electrical circuit, the charges stored on the plates of the capacitor move towards each other, resulting in a current flow. This movement of charges occurs due to the potential difference across the capacitor being reduced and the charges seeking to equalize or balance the electric potential.
4. The findings and assumptions that make up a model of the behavior of electricity include:
a) Electric charges exist and can be positive or negative.
b) Like charges repel each other, and opposite charges attract each other.
c) Electric fields exist and exert forces on electric charges.
d) Electric current is the movement of electric charges through a conductor.
e) Current flows from higher potential to lower potential.
f) Ohm's Law relates current, voltage, and resistance in a circuit.
g) Conservation of charge - the total electric charge in a closed system is constant.
h) Kirchhoff's laws govern the behavior of circuits, including the conservation of energy and charge.
These findings and assumptions collectively form the foundation for understanding and predicting the behavior of electricity in various circuits and systems.