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...
decrease to half of its original value
That won't work. To convert an ammeter (a galvanometer is a very sensitive type of ammeter) you connect a high value resistor in series with it.
It depends on the configuration of the ammeter. If you have an ammeter with red on one side, green on the other, and a balance point in the center, the needle will go into the red when when load is increased in relation to the charge. If the load is decreased in relation to the charge, the needle will go into the green. If you have an ammeter with a numerical value (i.e. 30, 40, 50, etc.) then the needle will go up to the value of the load present in the system not in relation to the charge.
Connecting an ammeter in parallel subjects that ammeter to the full supply voltage. The shunt resistor is not designed to sustain that value of voltage and will burn out. Also, the clue is in the word 'shunt' (which means 'in parallel') which means that the coil will also burn out!
An ammeter has to measure to current flowing through the circuit. Resistance offers an obstruction to the current flow. So, if the resistance of an ammeter is large , the current measured by the ammeter will be quite less as compared to the actual amount of current flowing through the circuit which is undesirable. If ammeter has zero resistance , then it will give the exact value of current. But this is not practically possible because every material has some value of internal resistance which we can't control. For this reason , ammeter must have small 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...
Actually ammeter is a galvanometer which is shunted by a resistance called shunt. For large currents major part of it is bypassed through the shunt. The parallel combination of shunt resistance and meter resistance is added to the circuit resistances , so the value indicated by the ammeter is slightly lesser than the actually value.
an ideal ammeter has zero or negligible resistance when this is connected in series no effective resistance would be added in the circuit so that the value of curret that we get is exactly of the circuit only. but when the ammeter is connected in parllel as it has zero resistance , the resistor to which it is connected in parllel gets shorted and due to his the effective resistance of the circuit is changed and so the effective current ... due to this the w=value measured by the ammeter would be different (incresed due to dec. in effective resistance)
we can measure the resistance of the motor by using voltmeter ammeter method of by directly using a multimeter across the armature terminals of the motor in voltmeter ammeter method we should use a less value of dc voltage to find the resistance
The ammeter is basically a Galvanometer with a small resistance to parallel with it. As we know that, if we connect two resistances in parallel, then the equivalent resistance is equal to the the value which is less than the value of lowest resistance connected in parallel. suppose if we connect 1 ohm & 0.1 ohm in parallel, then the equivalent of it will be 0.0909 ohm (less than 0.1 ohm). means in parallel circuit the equivalent resistance become smaller. as like this a small parallel resistance across galvanometer decreases the value of the value of resistance of it. since it gets very small value, so it connected in series to measure the value of current in the circuit. due to very low resistance, it drops very low voltage on it ( upto can be negligible) so we assume that it works like a short circuit.
To by pass the extra current from the limit of Galvano meter & this parallel resistance value depend upon the by passed current.
decrease to half of its original value
By attaching a resistance in parallel connection with the galvanometer. Or when a low resistor connected in parallel with galvanometer ,the galvanometer is converted in ammeter. and the resistor is called shunt resistance.
That won't work. To convert an ammeter (a galvanometer is a very sensitive type of ammeter) you connect a high value resistor in series with it.
If the resistance is increased the current, which is inversely proportional, decreases and, the voltage drop increases.
it explodes and burns everyone in the room.