Question

Помогите плиз!!!1)Приведите пример цепи, которая не сводится к комбинации после- довательных и параллельных соединений.2)В каких случаях параллельно амперметру присоединяют шунт, а к вольтметру последовательно присоединяют добавочное сопротивление?

Answer 1

IШунт присоединяется параллельно амперметру для того чтобы измерить ток больше чем предел измерения прибора
Дополнительное сопротивление подключается последовательно с вольтметром для расширения предела измерения напряжения вольтметром
Схему могу предложить но это надо рисовать
(на словах два последовательно, параллельно им еще два последовательно, взять две точки межу последовательными и соединить пятым резистором ( мостовая схема)

Answer 2

Example of a chain that cannot be reduced to a combination of series and parallel connections:

An example of a chain that cannot be reduced to a combination of series and parallel connections is a bridge circuit. A bridge circuit consists of four resistors connected in a diamond shape, with each resistor forming one side of the diamond. The resistors are connected in such a way that there are two parallel branches and two series branches. This configuration cannot be reduced to a combination of series and parallel connections because it has a unique circuit topology. The bridge circuit is commonly used in applications such as strain gauge measurements and impedance measurements [[1]].

Cases where a shunt is connected in parallel to an ammeter and an additional resistance is connected in series to a voltmeter:

In electrical circuits, ammeters are used to measure current, while voltmeters are used to measure voltage. In certain cases, it is necessary to connect additional components to these instruments to ensure accurate measurements.

Parallel connection of a shunt to an ammeter: When measuring high currents, the ammeter may not have a high enough current rating to directly measure the current. In such cases, a shunt resistor is connected in parallel to the ammeter. The shunt resistor diverts a portion of the current, allowing the ammeter to measure only a fraction of the total current. By knowing the resistance value of the shunt and the measured current, the total current can be calculated using Ohm's law [[2]].

Series connection of an additional resistance to a voltmeter: Voltmeters are designed to measure voltage across a component or a part of a circuit. However, in some cases, the voltmeter itself may have a non-negligible resistance, which can affect the accuracy of the voltage measurement. To minimize this effect, an additional resistance, known as a loading resistor, is connected in series with the voltmeter. The loading resistor helps to reduce the impact of the voltmeter's internal resistance on the voltage being measured [[3]].

These additional components, the shunt and the loading resistor, are connected in specific ways to ensure accurate measurements and to minimize the impact on the circuit being measured.

I hope this helps! Let me know if you have any further questions.