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How much resistance must be placed in a 240 volt circuit in order to limit the power to 480 watts?
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Why should a millimeter have a low resistance?
An ammeter is placed in series with a circuit in order to measure the current. If it has any appreciable resistance, inserting the ammeter will increase the normal resistance of the circuit and reduce the value of the current flowing through it. The ammeter will, therefore, give an inaccurate reading (under-read). So the ammeter must have a very low resistance so that it has the minimum effect on the normal resistance of the circuit being tested. Ideally, the ammeter should have zero resistance but, of course, this is impossible.
How much resistance must be placed in a 110 volt circuit in order to limit the current to 2 amps?
Ohm's Law: Resistance = Voltage divided by current110 volts / 2 amperes = 55 ohmsNote: This represents 220 watts, which is a considerable amount of power for a resistor. In all likelihood, the resistance will change as a result of that amount of power (heat) so the end result, 55 ohms, is only valid as an absolute number, in that 55 ohms is the answer, but the cold value of the resistor is uncertain.
Why one of the leads of resistor connected in electronic circuit is opened while measuring its resistance?
You open one of the leads of resistor connected in electronic circuit while measuring its resistance in order to not introduce error cause by other components in the circuit.
Does a volt meter takes power from the system?
No it does not. A volt meter only reads the current that is passing through it.AnswerAll instruments draw some (albeit tiny) current from the circuit under test in order to operate. So, if this is what you mean by 'taking power from circuit', then the answer is yes, it does.Instruments also change the normal resistance of the circuit being tested -for example, ammeters increase the resistance of the circuit into which they are connected, while voltmeters decrease the circuit resistance across which they are connected. So adding a voltmeter (or an ammeter) to a circuit affects the operation of that circuit to some degree. To minimise this interference, it is important that an ammeter's internal resistance is very much lower than the circuit's resistance, and a voltmeter's resistance is very much higher than the circuit's resistance.
What is the equivalent resistance through the entire circuit?
The equivalent resistance is the overall effect all of the resistances in a circuit has. Put another way, it is the value a single resistor in a circuit would have to be in order to have the same effect as all of the resistors resistors combined in a given circuit.
How is an ammeter connected in a circuit in order to read the current flowing in the circuit?
In series with the circuit and never in parallel. The reason being that it will cause the circuit total resistance to drop which will make the circuit draw excessive current. That's a short circuit actually.
Why are resistance materials used in toasters?
Because the main purpose of a toaster is to radiate heat. In order to generate heat from electric current, resistance is required in the circuit.
What happened when you turned on the switch of the light?
A switch is placed in an electrical circuit in order to place a gap when the switch is off, so the circuit is broken. When the switch is on, the circuit is complete and the electricity can flow round the circuit.
What is purpose of a resistance in a circuit?
It doesn't necessarily have any purpose. It is a natural feature of any circuit, and caused by the length, cross-sectional area, and resistivity of the conducting material. In other words, it exists, whether we want it or not! Ideally, it would be a good thing if resistance didn't exist in supply cables, as it causes a voltage drop along the cable, and is responsible for energy losses. 'Resistors', on the other hand, are circuit components having specific values of resistance, which can be added to a circuit in order to modify the natural resistance of that circuit.
What is the resistance you n the circuit when 10v2k greek symbol along with4k greek symbol?
In order to calculate the effective combined resistance, we need to know whether they are connected in series or in parallel. We don't know which circuit configuration is indicated when you say "along with".
Does a fuse have a low resistance?
Yes, fuses have a low resistance in order to not dominate the consumption of the circuit's power, such that the desired appliance wired in series with the fuse consumes the bulk of the power.
Why you do insulation resistance test?
in order to avoid unwanted short circuit break downs.... short circuit can burn the transformer and motor winding.... Megger is the device used to check the insulation .
