Question

7. Опір усіх резисторів на ділянці електричного кола (рис. 3) одна- ковим і дорівнює 5 Ом. До ділянки кола прикладено постійну на пругу. Який ключ потрібно замкнути, щоб показ амперметра був нижчим від показу амперметра А,? Яке значення сили струму буде показувати амперметр А1, якщо замкнути тільки ключ К,? В домо що амперметр А2, показує 300 мА, якщо всі ключі розімкнені. ПОМОГИТЕ ПОЖАЛУЙСТА ​

Answer 1

Ответ:


Для того, щоб показ амперметра А1 був меншим від показу амперметра А, потрібно замкнути ключ К2. Тоді струм буде розподілятись між резисторами R2 і R3, і частка струму, що протікає через R3, буде меншою, ніж якщо був би замкнутий ключ К1.

Якщо замкнути тільки ключ К1, то струм буде протікати через всі три резистори, і його значення буде:

I = U / R = 10 В / (5 Ом + 5 Ом + 5 Ом) = 0,67 А

Амперметр А1 покаже таке ж значення струму, оскільки він підключений до ділянки кола, де протікає цей струм.

Якщо всі ключі розімкнені, то струм буде протікати через всі три резистори, і його значення буде таким:

I = U / R = 10 В / (5 Ом + 5 Ом + 5 Ом) = 0,67 А

Амперметр А2 покаже таке ж значення струму, оскільки він підключений до ділянки кола, де протікає цей струм.

Answer 2

Understanding the Question

The question is asking about the resistance of all the resistors in an electric circuit and the actions needed to change the current readings on two ammeters (A and A1) in the circuit. The circuit diagram is not provided, but it is mentioned that the resistance of a certain section of the circuit is 5 ohms. The question also asks for the current reading on ammeter A1 when a specific switch (K) is closed, and the current reading on ammeter A2 when all switches are open.

Answer

To answer the question, we need to understand the circuit configuration and the impact of closing or opening specific switches on the current readings. Unfortunately, the circuit diagram is not provided, so we cannot provide a specific answer. However, we can discuss the general principles that apply to electric circuits and how different components affect the current flow.

Electric Circuit Basics

An electric circuit consists of various components, including resistors, switches, and a power source. The flow of electric current in a circuit is determined by the resistance and the voltage applied. The current can be calculated using Ohm's Law: I = V/R, where I is the current, V is the voltage, and R is the resistance.

Impact of Resistance on Current

In a series circuit, the total resistance is equal to the sum of the individual resistances. If the resistance of the section mentioned in the question is 5 ohms, it means that the total resistance of that section is 5 ohms. However, we don't have enough information to determine the resistance of the other components in the circuit.

Impact of Switches on Current Readings

The question asks about the impact of closing or opening specific switches on the current readings of ammeters A and A1. Without the circuit diagram, it is difficult to provide a specific answer. However, we can discuss the general principles.

- Closing a switch: When a switch is closed, it completes the circuit and allows current to flow through the connected components. This can increase the current reading on the ammeter connected to that section of the circuit. - Opening a switch: When a switch is open, it breaks the circuit and interrupts the flow of current. This can decrease the current reading on the ammeter connected to that section of the circuit.

Current Reading on Ammeter A1

The question asks for the current reading on ammeter A1 when switch K is closed. Without the circuit diagram, we cannot determine the specific current reading. However, if switch K is connected to a section of the circuit with a resistance of 5 ohms, closing the switch may increase the current reading on ammeter A1, depending on the resistance of the other components in the circuit.

Current Reading on Ammeter A2

The question states that ammeter A2 shows a reading of 300 mA when all switches are open. Without the circuit diagram, we cannot determine the specific current reading. However, if all switches are open, it means that the circuit is not complete, and no current can flow. Therefore, the current reading on ammeter A2 should be zero.

Conclusion

In conclusion, without the circuit diagram, we cannot provide specific answers to the question. However, we have discussed the general principles of electric circuits and the impact of resistance and switches on current flow and current readings. To determine the specific current readings, it is necessary to have the circuit diagram and information about the resistance values of all the components in the circuit.