How to calculate the ammeter readings in a circuit?
When the load is actually 200 Amperes, the ammeter connected at the output terminals of the Current Transformer will show 5 Amperes. Then to get the actual Load Current of the circuit, a simple COMPUTATION is done as: Load Current = 5 amp reading X CT ratio = 5 X 40 = 200 Amperes. Most of the time using Ohms Law.
How to convert an ammeter to a voltmeter?
Key points
- An ammeter is a low resistance instrument and it is always connected in series to the circuit
- An ideal ammeter has zero resistance
- In order to increase the range of an ammeter n times, the value of shunt resistance to be connected in parallel is S =G/n-1
How to read a voltmeter correctly?
Part 2 Part 2 of 3: Measuring Voltage
- Hold the probes safely. Do not touch the metal probes while connecting them to a circuit. ...
- Touch the black test lead to one part of the circuit. Test circuits for voltage by attaching the leads in parallel.
- Touch the red test lead to another point on the circuit. ...
- Raise the range if you get an overload reading. ...
- Adjust the voltmeter if necessary. ...
How do you find the internal resistance of an ammeter?
The ammeter reads the entire current flowing through the internal resistance of the voltmeter, and the voltmeter reads the voltage drop across this resistance, so r i = V/i. You can check this by inserting a resistance decade box in series with the circuit and adjusting the resistance until the meter readings go to one half their former values. The decade box will then read the internal resistance of the voltmeter (assuming that of the ammeter is much smaller).
What is the difference between a voltmeter and an ammeter?
A voltmeter measures voltage parallel to the circuit being tested. An ammeter measures current in series with the circuit. In an automobile this means the voltmeter reads the voltage potential between the battery and the chassis of your vehicle.
Where do you put the ammeter in a circuit?
This is a simplified circuit, but applies to any circuit. You put the ammeter in the part of the circuit you want to measure the current in. You put the voltmeter across the part or parts of the circuit you want to measure the voltage difference.
What does a voltmeter measure?
If there is a battery you may measure across it to measure the driving voltage of the circuit.
Why is a voltmeter in parallel?
The reason it is in parallel is because you want to read the voltage drop across a component as opposed to an ammeter which would read the current through a component. 1.3K views.
Why is an ammeter connected in series?
An ammeter is connected in series with the circuit because the purpose of the ammeter is to measure the current through the circuit. Since the ammeter is a low impedance device (as ammeters are not supposed to block the current flowing through the circuit affectin. Continue Reading.
How to use an ammeter?
In order to use an ammeter, you need to break (cut) the circuit and insert the ammeter between the points of the cut. About the simplest circuit there is, with ammeter and voltmeter connected. There is an exception, though.
Why are ammeters a nuisance?
Therefore ammeters are a nuisance in testing because of the need to open the circuit to wire in the ammeter. If the current is AC rather than DC, the AC current can be read without opening the wire using the principle of a 1-turn transformer.
Why is an ammeter connected in series and a voltmeter connected in parallel?
It is a very low resistance (nearly zero) device. If it will be connected in parallel, it would draw most of the current and would get damaged. Hence, it is connected in series.
What is a voltmeter?
A voltmeter is a device which measures the amount of potential difference across a resistor or a series of resistors. It is a very high resistance (nearly infinite) device. If it will be connected in series, it would would increase the equivalent resistance of the circuit to nearly infinite and no current would. flow through the circuit.
