How to Make a Galvanometer
Select a compass., Wrap the compass with wire., Strip and prep the wire ends., Connect one wire end to a battery’s positive terminal., Connect to the battery’s negative terminal., Watch the needle., Read about the Oersted experiment., Consider that...
Step-by-Step Guide
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Step 1: Select a compass.
A compass has a magnetic needle.
This needle will allow you to detect electrical currents because electrical currents generate a magnetic field (and this field interacts with the needle).
The most effective compass will be one meant for navigational purposes (i.e. designed to align to the earth’s magnetic field and point north), rather than a toy.You can buy a compass online, an outdoor recreation store, or at some large general stores. -
Step 2: Wrap the compass with wire.
Use about twelve inches of thin, insulated copper wire.
Keep in mind that the tighter you wrap the wire around the compass, the more turns (wraps) you will get.
Since you are coiling the wire around the compass, more turns translates to a stronger magnetic field being produced.
Be sure that you leave two leads about three inches long (one on either end of the wire)., First, you should use wire strippers to remove any plastic or other insulation from both ends of the wire, leaving an inch of wire exposed.
Next, make sure that the wire is clean by sanding it gently with sandpaper.
Wires are often coated with films or chemicals that you cannot see to prevent them from corroding.
Unfortunately, if you don’t sand this off, it can hinder the flow of electricity., Batteries store power by creating an electrical gradient.
That is to say that one side of the battery is positively charged and the other side is negatively charged.
The two sides are separated by an insulator.
By touching your wire (a conductor) to both sides, you will create a path for this charge to move.
First, touch one end of the wire to the positive terminal.The positive terminal of the battery will be marked with a plus sign. , Doing this will close the circuit and allow the charge in the battery to flow.
Flowing charge is an electrical current.
To create this current, touch the second wire end to the negative terminal while holding the first on the positive.
Remove either end to stop the current.The negative terminal of the battery will be marked with a negative sign.
It is a good idea to wear gloves for this part of the experiment.
This will help prevent shocks and/or burns.
The current flow will make the battery and wires very hot in just a few seconds.
Leave the wire connected to the battery just long enough to watch the compass spin. , Now that you’ve generated an electric current, a magnetic field will also be created.
This magnetic field will cause the needle in the compass to move.
When the needle moves, you will know that you are detecting an electrical current., Hans Christian Oersted was the first to show that magnetic fields were induced by electrical current.
He built a galvanometer using copper wire and a compass to show that the needle moved when a current was passed through the wire.
This is the science on which galvanometers work., Magnetic fields have a magnitude (how strong the field is) and a direction.
The direction is important, because it governs how and where the needle moves.
The magnitude of the field can affect how fast the needle moves.
For example, if you line the compass needle parallel to the coil and then turn on the current, the needle will be repelled., To replicate the way that the needle moves away from the coiled wire, you can try to put two magnets together with the same end (negative or positive) facing each other.
The like charges will repel and push them away from each other in the same way that the needle is repelled by the copper wire. -
Step 3: Strip and prep the wire ends.
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Step 4: Connect one wire end to a battery’s positive terminal.
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Step 5: Connect to the battery’s negative terminal.
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Step 6: Watch the needle.
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Step 7: Read about the Oersted experiment.
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Step 8: Consider that magnetic fields are vectors.
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Step 9: Observe how similar charges repel each other.
Detailed Guide
A compass has a magnetic needle.
This needle will allow you to detect electrical currents because electrical currents generate a magnetic field (and this field interacts with the needle).
The most effective compass will be one meant for navigational purposes (i.e. designed to align to the earth’s magnetic field and point north), rather than a toy.You can buy a compass online, an outdoor recreation store, or at some large general stores.
Use about twelve inches of thin, insulated copper wire.
Keep in mind that the tighter you wrap the wire around the compass, the more turns (wraps) you will get.
Since you are coiling the wire around the compass, more turns translates to a stronger magnetic field being produced.
Be sure that you leave two leads about three inches long (one on either end of the wire)., First, you should use wire strippers to remove any plastic or other insulation from both ends of the wire, leaving an inch of wire exposed.
Next, make sure that the wire is clean by sanding it gently with sandpaper.
Wires are often coated with films or chemicals that you cannot see to prevent them from corroding.
Unfortunately, if you don’t sand this off, it can hinder the flow of electricity., Batteries store power by creating an electrical gradient.
That is to say that one side of the battery is positively charged and the other side is negatively charged.
The two sides are separated by an insulator.
By touching your wire (a conductor) to both sides, you will create a path for this charge to move.
First, touch one end of the wire to the positive terminal.The positive terminal of the battery will be marked with a plus sign. , Doing this will close the circuit and allow the charge in the battery to flow.
Flowing charge is an electrical current.
To create this current, touch the second wire end to the negative terminal while holding the first on the positive.
Remove either end to stop the current.The negative terminal of the battery will be marked with a negative sign.
It is a good idea to wear gloves for this part of the experiment.
This will help prevent shocks and/or burns.
The current flow will make the battery and wires very hot in just a few seconds.
Leave the wire connected to the battery just long enough to watch the compass spin. , Now that you’ve generated an electric current, a magnetic field will also be created.
This magnetic field will cause the needle in the compass to move.
When the needle moves, you will know that you are detecting an electrical current., Hans Christian Oersted was the first to show that magnetic fields were induced by electrical current.
He built a galvanometer using copper wire and a compass to show that the needle moved when a current was passed through the wire.
This is the science on which galvanometers work., Magnetic fields have a magnitude (how strong the field is) and a direction.
The direction is important, because it governs how and where the needle moves.
The magnitude of the field can affect how fast the needle moves.
For example, if you line the compass needle parallel to the coil and then turn on the current, the needle will be repelled., To replicate the way that the needle moves away from the coiled wire, you can try to put two magnets together with the same end (negative or positive) facing each other.
The like charges will repel and push them away from each other in the same way that the needle is repelled by the copper wire.
About the Author
Edward Myers
Specializes in breaking down complex pet care topics into simple steps.
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