V. Complete the sentences using the text: 1. The potential difference must be maintained by …
2. Materials that offer slight opposition are called …
3. The best insulators are …
4. There are various kinds of electric circuits such as …
5. We “open” the circuit when …
6. We “close” the circuit when …
7. The “short” circuit is produced when …
8. A fuse is …
VI. Answer the questions:
1. What concepts are very important in study of electric current?
2. What forms an electric circuit?
3. What materials are the best conductors and insulators?
4. What kinds of electric circuits do you know?
5. How can we open and close the circuit?
6. When are electrical devices connected in series?
7. What is an example of a series circuit?
8. What can you say about «parallel» circuits?
9. What does the short circuit often result from
2. Materials that offer slight opposition to the flow of electric current are called conductors. Conductors allow electricity to pass through them relatively easily, such as metals like copper and aluminum.
3. The best insulators are materials that offer high resistance to the flow of electric current. Insulators prevent or hinder the flow of electricity, such as rubber, plastic, and glass. These materials are used to cover wires to prevent electric shocks and protect the wiring from damage.
4. There are various kinds of electric circuits such as series circuits, parallel circuits, and combination circuits. In a series circuit, the components are arranged in a linear manner, so the current passes through each component one after the other. In a parallel circuit, the components are connected across multiple paths, allowing the current to divide and flow through each path independently. Combination circuits are a mixture of series and parallel circuits.
5. We "open" the circuit when we disconnect the flow of current by either removing a component or breaking the connection. This breaks the path for the current to flow and stops the flow of electricity.
6. We "close" the circuit when we complete the path for the current to flow by reconnecting the circuit or adding a component. This allows the current to flow through the circuit again.
7. A "short" circuit is produced when there is a low resistance path that bypasses the intended components in a circuit. This can cause a large amount of current to flow, which can lead to overheating, damage to the components, or even fires. A short circuit often occurs due to faulty wiring or damaged insulation.
8. A fuse is a safety device that is placed in series with an electrical circuit. It is designed to melt and break the circuit if there is an excessive current flow. This helps to protect the circuit from damage and prevent overheating or fire hazards.
VI. Answer the questions:
1. The concepts that are very important in the study of electric current include potential difference, resistance, conductors, insulators, series and parallel circuits, and safety measures such as fuses.
2. An electric circuit is formed by connecting various components, such as wires, batteries, resistors, and switches, in a closed loop. This allows the flow of electric current from the power source to the load or device being powered.
3. The best conductors of electricity are materials that have low resistance, such as metals like copper and silver. The best insulators are materials that have high resistance, such as rubber and plastic.
4. The kinds of electric circuits include series circuits, parallel circuits, and combination circuits.
5. We can open and close a circuit by either disconnecting or connecting the components or wires in the circuit. For example, to open a circuit, we can remove a component or break the connection, while to close a circuit, we can reconnect the components or complete the connection.
6. Electrical devices are connected in series when they are arranged one after the other in a single path. This means that the same current flows through each device in the circuit.
7. An example of a series circuit is a string of Christmas lights, where each light is connected in series and if one light goes out, the entire string will not work.
8. "Parallel" circuits are those where the components are connected across multiple paths, allowing the current to flow independently through each path. In a parallel circuit, the voltage across each component is the same, but the current can divide among the different paths.
9. The short circuit often results from faulty wiring or damaged insulation. When the insulation is damaged, it creates a low resistance path that bypasses the intended components, causing a large amount of current to flow. This can lead to overheating and damage to the circuit.