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Kirchoff's Voltage and Current Laws apply to all AC circuits as well as DC circuits. Other laws, such as Ohm's law and Norton and Thevanin equivalents apply equally as well.
The complicating factor is that, at AC, current and voltage are not usually in phase with each other, unless it is a simple resistive circuit. That makes the math harder, but it does not make it invalid or impossible.
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What is external resistance?
External voltage is the ration when there is an increase in current and voltage. If you apply voltage to the outside of a circuit and need to figure out the amount of current flow, that would be the external resistance.
Why Kirchhoffs current law and Kirchhoffs voltage law cannot apply on distributed circuits?
Actually, they do apply.Kirchoff's Current Law states that the signed sum of the currents entering a node is zero. This applies whether the node has only two connections, such as in a series cicuit, or more than two connections, such as in a parallel circuit. Some people confuse this with the rule that current at every point in a series circuit is the same. That is just a special case of KCL, but the real rule has to do with the node, and not the circuit.Kirchoff's Voltage Law states that the signed sum of the voltage drops going around a series circuit is zero. This applies for simple series circuits as well as for complex series/parallel circuits. Pick any loop in a circuit and walk around it - you will find that the signed sum of the voltage drops is zero, no matter what.
How do you use thevenin's theorem to calculate current in resistors?
If this is an independent current source, it has to be disconnected.Independent voltage sources are replaced by a short-circuit.More about this at (see Related links):MasteringElectronicsDesign.com: How to Apply Thevenin's Theorem - Part 1, Solving Circuits with Independent SourcesandMasteringElectronicsDesign.com: How to Apply Thevenin's Theorem - Part 2. Nested Thevenin Sources Method
Do the ohm's law applies to all types of electrical circuits?
No. Ohm's Law only applies to linear or ohmic circuits. Ohm' Law is a law of constant proportionality -that is, the ratio of voltage to current must be constant over a wide range of voltage variation. In other words, if you varied the voltage and measured the resulting current, the result would be a linear (straight line) graph. If the resulting graph is not a straight line, then the ratio of voltage to current is not a constant, so Ohm's Law does not apply -such circuits are called 'non-linear' or 'non-ohmic'. Most metal conductors obey Ohm's Law over a reasonably-wide variation in applied voltages, but many don't -for example, tungsten does not obey Ohm's Law. Many electronic circuits, including diodes, etc., are non-linear, as are electrolytes.The equation R = V/R applies in all circumstances -it will always tell you what the circuit's resistance happens to be for that particular ratio of voltage to current. It must be understood that this equation is NOT, as many think, 'the equation for Ohm's Law', but is derived from the definition of the ohm.
What is knee point voltage of current transformer?
10 % increase in voltage gives you 50 % increase in excitation current is called knee point voltage. To measure this first demagnetise the CT and apply voltage gradually from secondary keeping primary winding open circuited. while doing this above phenomeneo will be obsesrved.
Does Kirchhoff current law and Kirchhoff voltage law depend on the relationship between current and voltage in a resistor?
Kirchhoff's Voltage and Current Laws apply to circuits: series, parallel, series-parallel, and complex.If your circuit comprises just a single resistor, then they still apply. For example, the voltage drop across a single resistor will be equal and opposite the applied voltage (Kirchhoff's Voltage Law), and the current entering the resistor will be equal to the current leaving it (Kirchhoff's Current Law).
How are current and voltage related to the power supplied by the source?
in ac circuits power,P=VICOS@ @ is the angle between voltage and current. in dc P=VI V is the voltage I is the current. Power (in Watts) is current (A) x voltage (V)
How do you measure the continuty of electrical circuits?
Apply a small voltage between the ends of the circuit, and check for the presence of a small current. This procedure is implemented in the test instrument known as the "ohm-meter".
Why is there a difference in current in a coil when you apply dc voltage and then AC voltage to it?
A coil has both resistance and inductance. When you apply a d.c. voltage, the opposition to current is the resistance of the coil. When you apply an a.c. voltage, the opposition to current is impedance -the vector-sum of the coil's resistance and its inductive reactance. Inductive reactance is proportional to the inductance of the coil and the frequency of the supply.
What is Ohm's law in a direct circuit?
Ohm's Law is a law of constant proportionality, and only applies to circuits in which the ratio of voltage to current is a constant over variations in applied voltage. Such circuits are called linear or ohmic circuits, and include most metals. However, in the case of metals such as tungsten, for electronic devices such as diodes, and for electrolytes, Ohm's Law does NOT apply, and we call such circuits 'non-linear' or 'non-ohmic'. For linear circuits, Ohm's Law simply states that the current flowing through that circuit is directly proportional to the voltage applied across its ends. The equation R = V/I is not, as many think, derived from Ohm's Law, but from the definition of the ohm.
What is external resistance?
External voltage is the ration when there is an increase in current and voltage. If you apply voltage to the outside of a circuit and need to figure out the amount of current flow, that would be the external resistance.
How do we usually think of voltage as the cause and currents the effect?
You apply a voltage across a load and the result is that a current flows through the load. So you must have the voltage present, the cause, before current flow, the effect. Think of voltage as pressure and current as flow.
How to find resistance?
-- Apply a small, known voltage between the terminals of the device. -- Measure the current through the device with the voltage applied. -- Calculate the resistance of the device. It's (voltage) divided by (current).
What is the difference in the current and voltage?
Current (amperes) is the rate of flow of electric charge, in coulombs per second. Voltage, on the other hand, is the electric potential of that charge, in joules per coulomb.Current and voltage are related to resistance by Ohm's Law, which states that voltage is equal to current times resistance.There is a tendency to misuse the term "current", and to apply it, for instance as "an electric current of 120 volts". This usage is incorrect. Current is current, and voltage is voltage, as noted above.
How electrical resistance can be measured in copper and aluminium?
Same as for any other substance: Apply a voltage and measure the current flow. (Resistance equals voltage divided by the current flow.)
Why Kirchhoffs current law and Kirchhoffs voltage law cannot apply on distributed circuits?
Actually, they do apply.Kirchoff's Current Law states that the signed sum of the currents entering a node is zero. This applies whether the node has only two connections, such as in a series cicuit, or more than two connections, such as in a parallel circuit. Some people confuse this with the rule that current at every point in a series circuit is the same. That is just a special case of KCL, but the real rule has to do with the node, and not the circuit.Kirchoff's Voltage Law states that the signed sum of the voltage drops going around a series circuit is zero. This applies for simple series circuits as well as for complex series/parallel circuits. Pick any loop in a circuit and walk around it - you will find that the signed sum of the voltage drops is zero, no matter what.
How do you use thevenin's theorem to calculate current in resistors?
If this is an independent current source, it has to be disconnected.Independent voltage sources are replaced by a short-circuit.More about this at (see Related links):MasteringElectronicsDesign.com: How to Apply Thevenin's Theorem - Part 1, Solving Circuits with Independent SourcesandMasteringElectronicsDesign.com: How to Apply Thevenin's Theorem - Part 2. Nested Thevenin Sources Method
