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What is practical voltage source?
in case of ideal voltage source we consider the internal resistance to be zero.but in practical,every battery has some internal resistance then if you connect a load resistance across the terminals of that source,the net potential difference's across the voltage source will be a function of external resistance connects it won't give constant voltage across it's terminals.
Why an independent voltage source is deactivated by short circuiting it?
A voltage source (V) is modeled by connecting its internal impedance (Zg) in series. If we determine the impedance across the voltage source terminals, it should be Zg, and it is possible only if the voltage source is short-circuited.An equivalent current source is modeled by connecting the current source (V/Zg) in parallel with the internal impedance Zg. For the two sources to be equivalent, their impedances across their terminals must be equal. This is possible only if the current source is open-circuited.
How many things are needed to create a current?
A difference of potential (voltage) and a conductor connected to the voltage source will cause current flow. Not that you'd want to "short out" a voltage source with a piece of wire, but just the source of voltage and the conductor would permit current to flow. If you took a piece of wire and touched it to the terminals of a good battery, current would flow. It takes just those two things to create a current.
What is the difference between the terminal voltage and the source voltage?
the source voltage is the voltage that measured exactly after the voltage source , but the terminal voltage is the voltage that measured in the load terminals , which equal to the source voltage minus the drop voltage on the transmission line .
What is terminal voltage?
Terminal voltage is the voltage gotten at the terminals of the load in any system.
What is the off load voltage of the generator?
Terminal voltage is the voltage between the output terminals of a generator.
What is the current source replaced by open circuit across the terminals?
because an ideal current source is assumed to produce a constant current for any voltage and is assumed to have an impedence of infinity (open circuit).
Why do you replace voltage sources with short circuits and current sources with open circuits in thevenin's theorem?
The equivalent of an inactive Thevenin voltage source is a source with zero voltage between its terminals regardless of the current through it, best represented by a zero resistance, i.e. a short-circuit. The equivalent of an inactive Norton current source is a source through which no current can flow regardless of the voltage across it, best represented by an infinite resistance, i.e. an open circuit.
How can you get 12 volt dc from a 24 volt dc source?
Depends on the source. If your source is two 12v batteries in series you attach to the terminals of one battery only. Otherwise, you must drop the voltage by adding resistance to the circuit.
How do you calculate thevenis resistance in thevenis ckt?
First,remove all current and voltage sources ie replace voltage source with a short and keep current source open.Now draw the equivalent resistance-only circuit and find the equivalent resistance as viewed from the terminals of the circuit.
Why is the internal resistance of a voltage source made to be low?
When a voltage source, such as a battery or a generator, is on open circuit -in other words, when it is not supplying a load- the voltage appearing across its terminals is called its 'open circuit voltage' and corresponds numerically to its electromotive force.However, when the voltage source supplies current to a load, that current also passes through the voltage source itself. This causes an internal voltage drop, which is the product of this current and the voltage source's internal resistance. This voltage drop acts in the opposite direction to the electromotive force and reduces the source's terminal voltage. This internal voltage drop will increase, of course, if either the load current increases or the internal resistance increases.So, in order to keep that the source's internal voltage drop is as low as possible, its internal resistance must be as low as possible. In the case of a battery, the internal resistance is due to the ionic resistance of the electrolyte/plates, whereas in a generator it is due to the resistance of the windings.
How does an antenna convert electromagnetic waves into a current?
According to Faraday's law: "When current is passed through a conductor, an EM field is produced surrounding it." As an antenna contains one or more conductors, the terminals of which are connected to some voltage, when this voltage at the terminals is applied, it produces/induces the alternating current which radiates the elements in the electromagnetic field. (Transmission) The reverse of this occurs in reception; where the electromagnetic field from another source induces an alternating current in the antenna, and a corresponding voltage at the antenna's terminals.
