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The purpose of a voltmeter is to indicate the potential difference between two points in a circuit.When a voltmeter is connected across a circuit, it shunts the circuit. If the voltmeter has a low resistance,it will draw a substantial amount of current. This action lowers the effective resistance of the circuit andchanges the voltage reading.

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What is the resistance when switch is open?

Nothing will happen to the resistance of the circuit. However, with the switch open, it will be 'seen' as having infinite resistance from the supply side.


What will happen to resistance If amperage goes down and voltage remains the same?

The correct term is 'current', not 'amperage'. The answer is that nothing will happen to the resistance. Having said that, changing the resistance will cause current to change for a fixed value of voltage.Resistance is determined by the length, cross-sectional area, and resistivity of a material. Resistivity is affected by temperature, so resistance is also therefore indirectly affected by temperature. Only by changing one of these variables will the resistance change.Since the ratio of voltage to current will tell us what the resistance of a circuit happens to be (it's not affected by that ratio) for a particular ratio, the ratio will increase (as per your question) if the resistance increases. But it's not the ratio that's affecting resistance, its the resistance affecting the ratio!


When does a capacitor act as a resistor of infinite resistance?

When the frequency is zero(i.e when dc power is supplied), capacitor is open is treated as open circuit having infinite resistance.


What is the effect caused by ammeter resistance when an ammeter is inserted into a circuit to measure the current?

The effect the multimeter might have on the circuit when inserted to measure the current is to increase the circuit resistance and decrease the available voltage to the circuit. This is because the multimeter in amps or milliamps mode does have a small resistance which is not zero, so by Ohm's law, there is a voltage drop across the multimeter; small, but not zero. Usually this effect is small. One way to compensate is to start by measuring voltage, and then inserting a separate ammeter and adjusting the power supply to match the original voltage. Of course, the voltmeter must be downstream of the ammeter.


Do The resistance of a material generally increases as its temperature increases?

The answer to this depends on the material from which the resistance is made. For most materials resistance increases with increasing temperature. This is referred to as having a "positive temperature coefficient". Some materials have a negative temperature coefficient; these do have uses in electronics.

Related Questions

Why an ideal voltimer must infinity resistor?

An ideal voltmeter must have infinite resistance to prevent it from drawing any current from the circuit it is measuring. If it had finite resistance, it would alter the voltage across the component being measured, leading to inaccurate readings. By having infinite resistance, the voltmeter ensures that it does not influence the circuit, allowing for precise voltage measurements.


What is the resistance when switch is open?

Nothing will happen to the resistance of the circuit. However, with the switch open, it will be 'seen' as having infinite resistance from the supply side.


How you can minimize the loading effect on voltmeter?

To minimize the loading effect on a voltmeter, use a voltmeter with a high input impedance. This will ensure that the voltmeter draws as little current as possible from the circuit being measured, reducing the impact on the voltage being measured. Additionally, connecting the voltmeter in parallel with the circuit, rather than in series, can also help minimize the loading effect.


What would happen if you took hydrogen out of sugar?

Instead of having C6H12O6, you'd have C6O6. It's called cyclohexanehextone.


What will happen to resistance If amperage goes down and voltage remains the same?

The correct term is 'current', not 'amperage'. The answer is that nothing will happen to the resistance. Having said that, changing the resistance will cause current to change for a fixed value of voltage.Resistance is determined by the length, cross-sectional area, and resistivity of a material. Resistivity is affected by temperature, so resistance is also therefore indirectly affected by temperature. Only by changing one of these variables will the resistance change.Since the ratio of voltage to current will tell us what the resistance of a circuit happens to be (it's not affected by that ratio) for a particular ratio, the ratio will increase (as per your question) if the resistance increases. But it's not the ratio that's affecting resistance, its the resistance affecting the ratio!


What four factors determine the resistance of a material and give examples of each?

The four factors that determine the resistance of a material are resistivity (intrinsic property of the material), length (longer length increases resistance), cross-sectional area (smaller area increases resistance), and temperature (increases in temperature usually increase resistance). Examples could be copper with low resistivity, a longer wire having higher resistance, a thinner wire having higher resistance, and a material like a semiconductor having resistance affected by temperature changes.


A bulb is connected to a battery having a potential difference of 6 V A voltmeter is connected across the bulb What is the reading on the voltmeter when the bulb burns out?

Assuming you're referring to a simple incandescent bulb . . .When the bulb burns out, the filament is open, and it is electrically no longer there.The voltmeter is then across the battery, which is open circuited, i.e. without a load.The meter measures the open-circuit voltage of the battery, nominally 6 V.


What is the name of a semiconductor device having negative resistance?

A tunnel diode.


If amperage goes down and the voltage remains the same what happens to resistance?

The correct term is 'current', not 'amperage'. The answer is that nothing will happen to the resistance. Having said that, changing the resistance will cause current to change for a fixed value of voltage.Resistance is determined by the length, cross-sectional area, and resistivity of a material. Resistivity is affected by temperature, so resistance is also therefore indirectly affected by temperature. Only by changing one of these variables will the resistance change.Since the ratio of voltage to current will tell us what the resistance of a circuit happens to be (it's not affected by that ratio) for a particular ratio, the ratio will increase (as per your question) if the resistance increases. But it's not the ratio that's affecting resistance, its the resistance affecting the ratio!


Does current change in a circuit having bulb in series with a resistance?

Absolutely the more Resistance is put in series the less current Will flow.


What is the fire resistance rating for 8th inch steel plate?

Unprotected steel is generally not recognized as having a fire resistance rating.


Why you need resistance in series with led?

limit current and avoid having it explode