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First of all, in an active circuit, there are voltages flowing through various nodes. If you try to measure the resistor, those voltages will cause error in your meter, or may damage your meter. Second of all, even if you cut the power, any loop in the circuit around the resistor will affect the measured impedance. Unless you are certain that only the resistor will see the current introduced by the meter, you must take the resistor out of circuit to measure it.
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Why would never measure resistance in a circuit carrying a current?
If the circuit is carrying current then that means that the load (resistance) is in the circuit. if an ohm meter is connected in the live circuit then there would be some voltage drop at the ohm meter but as the meter has very less resistance, this would damage the instrument.
Where do you set the dial when you are measuring resistance on house current?
YOU DO NOT "measure resistance on house current".You never measure resistance of anything that has any path to any source ofpower ... not to a wall outlet, a battery, a windmill, a solar panel, etc. You onlymeasure resistance when all power is REMOVED from the circuit or componentyou're measuring. Then, the range you choose for the ohmmeter depends onthe component or circuit you're measuring, NOT on how it's powered when it'sturned on.
What is difference between ideal current source and practical current source?
Internal resistance. The ideal current source has no internal resistance in parallel with it (if it was set to supply no current it would act as an open circuit), and all the current it supplied would have to flow through its load (even if the load was an open circuit, in which case the voltage across the current source would be infinite). A real current source has the practical limitation that it must have an internal resistance in parallel with it, therefor some of the current it supplied is bypassed through that internal resistance and never reaches the load (if the load was an open circuit, then all the current supplied is bypassed and the resulting voltage drop across the internal resistance limits the voltage across the current source).
What meter must NEVER be connected to a circuit when the circuit power is turned on?
An Ohmmeter.
What is the impedence?
Impedance is the complex form of resistance. Impedance takes into account capacitance and inductance in a circuit as well. Impedance can be represented as resistance as a function of frequency.See link.AnswerImpedance is not a 'complex form of resistance'. It is the vector sum of a circuit's resistance and reactance. In electrical engineering, 'resistance' has a very specific meaning, and cannot be used to denote 'opposition'.
Why would never measure resistance in a circuit carrying a current?
If the circuit is carrying current then that means that the load (resistance) is in the circuit. if an ohm meter is connected in the live circuit then there would be some voltage drop at the ohm meter but as the meter has very less resistance, this would damage the instrument.
What will b the power factor of a series circut when r is made zero?
The power factor never depends on the resistance of a circuit. It depends on the equivalent inductance and capacitance in the circuit, and on the frequency of the power supply, even if the resistance is zero.
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.
In a series circuit is resistance constant?
current
Where do you set the dial when you are measuring resistance on house current?
YOU DO NOT "measure resistance on house current".You never measure resistance of anything that has any path to any source ofpower ... not to a wall outlet, a battery, a windmill, a solar panel, etc. You onlymeasure resistance when all power is REMOVED from the circuit or componentyou're measuring. Then, the range you choose for the ohmmeter depends onthe component or circuit you're measuring, NOT on how it's powered when it'sturned on.
Why current is measured in sereis?
It actually never is measured in series on a meter. AC can be measured by a meter clamp where is the coupling of flux can be measured. A normal meter will read the small voltage drop cause by current flowing through a series resistance. this small voltage drop will indicate current flow the magnitude is a function of scaling.
True or false if the voltage and resistance of a circuit stay constant the amperage can never change?
False. According to Ohm's Law, amperage (current) in a circuit is determined by the voltage and resistance. If either the voltage or resistance changes, the amperage will change accordingly to maintain a balance in the circuit.
Why should you never measure resistance in a circuit carrying a current?
Ideally true, but seldom so. The vast majority of resistance meters use current to measure resistance and just use V=IR to give R - the resistor is in a circuit carrying current. The only method that does not have a current through the resistance, it actually relies on the fact, is a Wheatstone bridge. The most important reason for not having a current is that you will be using a current in most cases, to meaure the resistance. Current from another source will screw the reading. Also, with a current flowing, you are not measuring resistance - you are measuring impedance - a combination of inductance and resistance.
What dose in parallel mean?
parallel means they will never cross each other. take a example when a resistance connected in parallel then a current flowing through it(both resistance) is not same depended on the value of each resistance. while in the series circuit current values is same for both resistance. parallel lines are drawn below:- series lines:- -------
How does a switch control an electric device?
A switch basically represents a gap in the electric circuit. Electric current can pass through a circuit only if it is complete. An incomplete circuit can never pass a current through it. When the switch is in the 'off' position, the circuit has a break (gap) in it. When you put the switch in 'on' position, the circuit wire join and the circuit gets completed.
What is difference between ideal current source and practical current source?
Internal resistance. The ideal current source has no internal resistance in parallel with it (if it was set to supply no current it would act as an open circuit), and all the current it supplied would have to flow through its load (even if the load was an open circuit, in which case the voltage across the current source would be infinite). A real current source has the practical limitation that it must have an internal resistance in parallel with it, therefor some of the current it supplied is bypassed through that internal resistance and never reaches the load (if the load was an open circuit, then all the current supplied is bypassed and the resulting voltage drop across the internal resistance limits the voltage across the current source).
What meter must NEVER be connected to a circuit when the circuit power is turned on?
An Ohmmeter.
