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Put questions to the following sentences.
1. An electrical network is an interconnection of electrical elements such as resistors, inductors, capacitors, and switches. 2. Linear circuits can be analysed to a certain extent by hand because complex number theory gives engineers the ability to treat all linear elements using a single mathematical representation. 3. Many engineers utilize special software to design and simulate circuits before building them.
Give the Definitions.
An electrical network, an electrical circuit.
Retell the text.
Text 14
Electrical laws
Vocabulary
law -закон
node -узловой пункт
equal - равный
potential differences - потенциальные различия
sum -сумма
resistance - сопротивление
branch -ветвь
conductance - проводимость
nonlinear - нелинейный
reactive - реактивный
linear self-regenerative heterodyning systems - линейные регенеративные
гетеродинные системы
A number of electrical laws apply to all electrical networks. These include
Kirchhoff s current law: the sum of all currents entering a node is equal to the sum of all currents leaving the node.
Kirchhoff s voltage law: the directed sum of the electrical potential differences around a circuit must be zero.
Ohm's law: the voltage across a resistor is the product of its resistance and the current flowing through it.
Norton's theorem: any two-terminal collection of voltage sources and resistors is electrically equivalent to an ideal current source in parallel with a single resistor.
Thevenin’s theorem: any two-terminal combination of voltage sources and resistors is electrically equivalent to a single voltage source in series with a single resistor.
Millman’s method: the voltage on the ends of branches in parallel is equal to the sum of the currents flowing in every branch divided by the total equivalent conductance.
Other more complex laws may be needed if the network contains nonlinear or reactive components. Non-linear self-regenerative heterodyning systems can be approximated. Applying these laws results in a set of simultaneous equations that can be solved either by hand or by a computer.
Exercises:
1. Give Russian equivalents of the following phrases:
A number of electrical laws, Kirchhoff s current law, the sum of ail currents, the product of its resistance, any two-terminal collection of voltage
sources, in parallel with a single resistor, a single voltage source, by the total equivalent conductance, other more complex laws, a set of simultaneous equations that can be solved either by hand or by a computer.
Complete the sentences.
1. The sum of all currents entering a node is equal to... 2.The directed sum of the electrical potential differences around a circuit... 3. Other more complex laws may be needed if the network contains... 4. Non-linear self-regenerative heterodyning systems... .