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What is the purpose of the series resistor in your designed ammeter circuit?
Wiki User
∙ 12y ago
You appear to be referring to a 'swamping resistor' which is connected in series with a moving-coil ammeter's moving coil.
To minimise any errors due to temperature changes in the resistance of the instrument's moving coil, the coil is connected in series with what is termed a 'swamping resistor' whose resistance is large in comparison with that of the moving coil, and which is manufactured from an alloy with a very lowtemperature coefficient of resistance (i.e. a metal whose resistance is hardly effected by wide variations in temperature).
For example, if the resistance of a 1-Ω moving coil increases to, say, 1.1 Ω, when its rated current flows through it, this will introduce a 10% error in the instrument's reading.
But by calibrating the instrument with a series swamp resistor of, say, 49 Ω, the overall resistance at rated current will become 50.1 Ω. This will result in an error of just 0.2%.
A swamping resistor, then, is an integral part of all moving-coil instruments and, when we refer to an instrument's 'coil resistance', we actually mean the combined resistance of the moving coil itself and its swamping resistor.
Wiki User
∙ 12y ago
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What are the function of ammeter?
The purpose of an ammeter is to sense and display the magnitude of the current flowing through it. When connected in series with a branch of an electrical circuit, the meter displays the magnitude (and direction) of the current in that path ... which you can't otherwise tell just by looking at the circuit.
What is need of capacitor and resistor in circuit?
because without using capacitor or resistor in a circuit,it cant be complete.Resistor is used to protect the circuit by giving a certain amount of voltage.Capacitor is used to charge and discharge purpose.
What is the usage of 330 ohm resistor?
No. It will not serve its intended purpose.
What happens if a circuit has no resistance?
Then the voltage in will equal the voltage out. The purpose of a resistor is to reduce the amount of electrical flow of current. You 'short out' the supply and blow a fuse/circuit breaker.
What is the purpose of a resistor in an electronic circuit If the resistor converts energy to heat then are you wasting energy any time you use a resistor?
In its simplest use a resistor in a circuit is used to limit the amount of current flow, or to decrease the amount of voltage applied to a device. One example is you had a 12 volt battery and you need/ wanted to connect it to a device that ran on 9 volts then a resistor can be chosen to reduce the 12 volts to the 9 volts required.
What instrument measures current in an electric circuit?
That's the purpose of the "ammeter".
How does a resistor TBA820 work?
The TBA820 is a 2 watt general purpose amplifier integrated circuit, not a resistor.
What are the function of ammeter?
The purpose of an ammeter is to sense and display the magnitude of the current flowing through it. When connected in series with a branch of an electrical circuit, the meter displays the magnitude (and direction) of the current in that path ... which you can't otherwise tell just by looking at the circuit.
What is need of capacitor and resistor in circuit?
because without using capacitor or resistor in a circuit,it cant be complete.Resistor is used to protect the circuit by giving a certain amount of voltage.Capacitor is used to charge and discharge purpose.
Why is it a very bad idea to connect an ammeter directly across a voltage source?
The ammeter is designed, on purpose, so as to have a very low resistance. Doing this will result in an excessive current.
How do you work air circuit breaker?
There are various to check if your air circuit breaker working. You can use various tools that are available to test your air circuit breaker. A clamping ammeter is ideal for this purpose.
What is the usage of 330 ohm resistor?
No. It will not serve its intended purpose.
How do you install a resistor in an DC circuit?
It depends on the purpose for installing the resistor. If the intent is to decrease current flow, the resistor must be connected in series with the load. If the purpose is to increase current flow, the resistor must be connected in parallel with the load. To connect a resistor in series, connect the resistor to one side of the power source, in line with the load. This will decrease circuit current flow. To connect a resistor in parallel, connect the resistor between the positive and negative sides of the power source, which will effectively connect the resistor across the load . This will increase current flow through the circuit. However, before connecting a component in parallel, make sure the increase in current flow will not exceed the current rating of the circuit or fuses/breakers will blow.
What is the purpose of a rheostat in the determination of an unknown resistor?
In a bridge circuit the unknown resistor is compared to the rheostat. When the meter across the bridge reads in the middle the unknown and the rheostat are the same value.
How you convert ammeter into voltmeter?
An ammeter measures the voltage across a resistor with a known value, andfrom that it calculates the current through the resistor. The resistor has to bea very small value, so that it doesn't change the current in the circuit by beingplaced in line with it.If you really want to do this, then you need a resistor made for the purpose,with a resistance of not more than 1 ohm. You can buy one, or maybe roll upa big ball of insulated wire that has a resistance of 1/2 or 3/4 ohm. (How youwould measure that accurately is another question.) When you have thatfractional-ohm resistor, connect the voltmeter across its ends, and you haveyour ammeter. To use it, open (break) the circuit whose current you want tomeasure, and connect your meter into the hole. Read the voltmeter. Thecurrent passing through your resistor is(the voltmeter reading) divided by (the resistance of your resistor).There are other design details to consider, which we won't go into at this time.If you actually try this, don't use it to measure currents greater than maybe1 Ampere. How will you know the current before you've measured it ? That'sexactly the appropriate question. The answer is: Experience. If you haven'tgot it, then maybe you shouldn't be building your own test equipment yet.
How do you convert voltmeter into ammeter?
An ammeter measures the voltage across a resistor with a known value, andfrom that it calculates the current through the resistor. The resistor has to bea very small value, so that it doesn't change the current in the circuit by beingplaced in line with it.If you really want to do this, then you need a resistor made for the purpose,with a resistance of not more than 1 ohm. You can buy one, or maybe roll upa big ball of insulated wire that has a resistance of 1/2 or 3/4 ohm. (How youwould measure that accurately is another question.) When you have thatfractional-ohm resistor, connect the voltmeter across its ends, and you haveyour ammeter. To use it, open (break) the circuit whose current you want tomeasure, and connect your meter into the hole. Read the voltmeter. Thecurrent passing through your resistor is(the voltmeter reading) divided by (the resistance of your resistor).There are other design details to consider, which we won't go into at this time.If you actually try this, don't use it to measure currents greater than maybe1 Ampere. How will you know the current before you've measured it ? That'sexactly the appropriate question. The answer is: Experience. If you haven'tgot it, then maybe you shouldn't be building your own test equipment yet.
What happens if a circuit has no resistance?
Then the voltage in will equal the voltage out. The purpose of a resistor is to reduce the amount of electrical flow of current. You 'short out' the supply and blow a fuse/circuit breaker.
