Question

Завдання 1. Опір кожного резистора на ділянці кола однаковий і дорівнює 20 Ом (рис. 1). 1. (2 бали) Визначте опiр дiлянки кола в разі, коли буде замкненим тільки ключ Ка: a) 20 Ом; б) 40 Ом; в) 10 Ом; г) 30 Ом. 2. (3 бали) Який ключ необхідно замкнути, щоб опiр дiлянки кола склав 60 Ом? 3. (3 бали) до дiлянки кола прикладено напругу 120 в. Які ключі необхідно замкнути, щоб амперметр по- казав 12 А?​

Answer 1

Task 1: Finding the Total Resistance of the Circuit

The total resistance of the circuit can be calculated using the formula for resistors in parallel, which is given by:

1/R_total = 1/R1 + 1/R2 + 1/R3 + ...

Given that each resistor has a resistance of 20 Ohms, the total resistance can be calculated when only the switch Ka is closed.

The total resistance of the circuit when only switch Ka is closed is 10 Ohms.

Task 2: Determining the Switch to Close for a Total Resistance of 60 Ohms

To achieve a total resistance of 60 Ohms, a combination of resistors needs to be connected in parallel. This can be achieved by closing switches in a specific configuration.

To obtain a total resistance of 60 Ohms, the switches Kb and Kc need to be closed, while switch Ka remains open.

Task 3: Determining the Switches to Close for a Current Reading of 12 A

When a voltage of 120 V is applied to the circuit, and an ammeter needs to read 12 A, the switches that need to be closed can be determined.

To achieve a current reading of 12 A, switches Ka and Kb need to be closed, while switch Kc remains open.

I hope this helps! If you have any further questions or need additional assistance, feel free to ask.