R = E / I
= (50 x 106) / (50)
= 1 megohm.
Strange for a "shunt". Must be across one heck of a meter movement !
It looks like the question was misworded. Instead of 50 megavolts, perhaps it should have been 50 millivolts. In that case the meter/shunt impedance would have been 0.001 ohms. In any case, the actual value of the shunt resistor would depend on the impedance of the meter itself. In the latter (assumed) case, this is probably negligible, so the shunt does appear to be 0.001 ohms.
You don't. ...unless you want to directly measure the current in a circuit branch. That's the purpose of an ammeter. You can also use a volt meter if you know the resistance of a resistor in that branch to determine current (assuming DC circuit here) - current = voltage / resistance. This may be more useful for circuitry that is on a breadboard, since inserting an ammeter may not be practical.
Voltage = (current) x (resistance) Current = (voltage)/(resistance) Resistance = (voltage)/(current)
Ohm's law states that "The current is directly proportional to the applied EMF (voltage) and inversely proportional to the resistance in the circuit." <<>> if resistor exists, resistance decreases according to ohm's law, current is directly proportional to voltage and current is inversely proportional to resistance it means as current increases, voltage increases. resistance increases, current decreases so as voltage if there is no resistor, there should be no resistance except internal resistance of voltmeter and ammeter
Ohm's Law: V = IR (voltage = current times resistance).Ohm's Law: V = IR (voltage = current times resistance).Ohm's Law: V = IR (voltage = current times resistance).Ohm's Law: V = IR (voltage = current times resistance).
The equivalent resistance you would have to place in series with an ideal battery (which of course does not exist) of the same voltage to get the same behavior (voltage drop with load) as the real battery has. It is a mathematical modeling technique to help in circuit analysis.
An ammeter is a low voltage voltmeter in parallel with a small resistance resistor. Current flow through the resistor creates a voltage drop across it which is then measured by the voltmeter.
An ideal ammeter is a device that measures electric current and has zero resistance, producing no voltage drop when connected in a circuit. This ensures that the current being measured is not affected by the presence of the ammeter itself, providing an accurate reading of the current flowing through the circuit.
The readings on an ammeter indicate the current being drawn by a load in a circuit. This load is basically a resistance to current flow. The higher the resistance, the lower the current. The supply voltage has a direct effect on current flow. The higher the voltage applied, the higher the current will be. So the readings will vary on the ammeter according to fluctuations in load and or resistance of the circuit and the applied voltage.
If you know the voltage and resistance, then current = voltage divided by resistance. Otherwise, you can attach an ammeter into the circuit (in series).
-- Connect a source of known, small voltage across the ends of the unknown resistance. -- Measure the resulting current through the unknown resistance. -- Divide (small known voltage)/(measured current). The quotient is the formerly unknown resistance.
One way to determine current is to measure it, with an ammeter. Another way is to calculate it using Ohm's law: current = voltage / resistance.
ammeter connect in series in circuit to measure the current, if the Ammeter have a high resistance it would effect the voltage value because there will be a drop voltage over the internal resistance of the Ammeter, so we desgin the ammeters with very low resistance...
I am going to assume that you mean low "resistance" in an open circuit test and are performing this with a multimeter. An ammeter works by place a very small amount of resistance in series with a circuit and then measuring the Voltage drop across the resistance. The Voltage is directly proportional to the current as given in ohms law: E = I x R If you are measuring the resistance through the ammeter it will have a very low resistance and impedance.
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.
Connecting an ammeter directly across a voltage source can cause a short circuit, damaging the ammeter and potentially causing overheating or even a fire hazard. This is because an ammeter has a low resistance, which could cause a very high current to flow through the circuit, overwhelming the device and damaging it. It is important to always connect an ammeter in series with the circuit to measure current accurately and safely.
You do use an ammeter in series. It has a very low resistance, which according to ohms law, makes it ideal for measuring current. You do not use a volt meter in series, as it has a very HIGH resistance and would not allow current to flow. You measure the voltage across a component (or components), and current through a circuit.
A: An ammeter actually is a voltmeter measuring the voltage drop across a very small shunt resistance. They can measure AC or DC, make sure the meter is rated for the anticipated current, and always connect in series.