Would a compass with unmagnetized needle work?
We know that the needle that is used in a compass is a permanently magnetized ferromagnetic material and commonly steel is used.
If we used an unmagnetized iron needle instead, would it still align with Earth's magnetic field lines? If yes, how?
magnetic-fields ferromagnetism
asked 2 hours ago
physicsguy19
726116
add a comment |
We know that the needle that is used in a compass is a permanently magnetized ferromagnetic material and commonly steel is used.
If we used an unmagnetized iron needle instead, would it still align with Earth's magnetic field lines? If yes, how?
magnetic-fields ferromagnetism
asked 2 hours ago
physicsguy19
726116
Why would you think “yes”?
– ZeroTheHero
2 hours ago
With the magnetic field of Earth no
– Alchimista
2 hours ago
add a comment |
We know that the needle that is used in a compass is a permanently magnetized ferromagnetic material and commonly steel is used.
If we used an unmagnetized iron needle instead, would it still align with Earth's magnetic field lines? If yes, how?
magnetic-fields ferromagnetism
asked 2 hours ago
physicsguy19
726116
We know that the needle that is used in a compass is a permanently magnetized ferromagnetic material and commonly steel is used.
If we used an unmagnetized iron needle instead, would it still align with Earth's magnetic field lines? If yes, how?
magnetic-fields ferromagnetism
magnetic-fields ferromagnetism
asked 2 hours ago
physicsguy19
726116
asked 2 hours ago
physicsguy19
726116
asked 2 hours ago
physicsguy19
726116
asked 2 hours ago
physicsguy19
726116
asked 2 hours ago
physicsguy19
726116
726116
Why would you think “yes”?
– ZeroTheHero
2 hours ago
With the magnetic field of Earth no
– Alchimista
2 hours ago
add a comment |
Why would you think “yes”?
– ZeroTheHero
2 hours ago
With the magnetic field of Earth no
– Alchimista
2 hours ago
Why would you think “yes”?
– ZeroTheHero
2 hours ago
Why would you think “yes”?
– ZeroTheHero
2 hours ago
With the magnetic field of Earth no
– Alchimista
2 hours ago
With the magnetic field of Earth no
– Alchimista
2 hours ago
add a comment |
2 Answers
2
active
oldest
votes
An unmagnetized iron needle will feel a force from the earth's field, but likely almost no torque about its center of mass. The force will be in the direction of the field's gradient, not in the direction of the field. The gradient of the earth's field is likely to be small and dominated by local irregularities.
answered 2 hours ago
Ben Crowell
48.3k4151292
add a comment |
A magnetic dipole would be induced in the iron bar and the iron bar would try and align itself along the magnetic field lines because of the torque applied on it by the interaction of the induced dipole and the Earth’s magnetic field.
However since the torque which was applied on the iron bar would be very small the chances are that there would not be an alignment even if you waited a long time.
answered 1 hour ago
Farcher
47.4k33696
In the first paragraph, you seem to be assuming that the induced magnetization would be along the length of the bar, but I don't see any reason why that would be true. It could be in any random orientation relative to the bar's long dimension. The effect would then be that the bar would experience a torque that would tend to return it to whatever orientation it had when it was first able to be magnetized (e.g., at the time when the iron was first cooled below the Fermi temperature). You're then describing a bar that is magnetized, which is contrary to the question.
– Ben Crowell
1 min ago
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
An unmagnetized iron needle will feel a force from the earth's field, but likely almost no torque about its center of mass. The force will be in the direction of the field's gradient, not in the direction of the field. The gradient of the earth's field is likely to be small and dominated by local irregularities.
answered 2 hours ago
Ben Crowell
48.3k4151292
add a comment |
An unmagnetized iron needle will feel a force from the earth's field, but likely almost no torque about its center of mass. The force will be in the direction of the field's gradient, not in the direction of the field. The gradient of the earth's field is likely to be small and dominated by local irregularities.
answered 2 hours ago
Ben Crowell
48.3k4151292
add a comment |
An unmagnetized iron needle will feel a force from the earth's field, but likely almost no torque about its center of mass. The force will be in the direction of the field's gradient, not in the direction of the field. The gradient of the earth's field is likely to be small and dominated by local irregularities.
answered 2 hours ago
Ben Crowell
48.3k4151292
An unmagnetized iron needle will feel a force from the earth's field, but likely almost no torque about its center of mass. The force will be in the direction of the field's gradient, not in the direction of the field. The gradient of the earth's field is likely to be small and dominated by local irregularities.
answered 2 hours ago
Ben Crowell
48.3k4151292
answered 2 hours ago
Ben Crowell
48.3k4151292
answered 2 hours ago
Ben Crowell
48.3k4151292
answered 2 hours ago
Ben Crowell
48.3k4151292
48.3k4151292
add a comment |
add a comment |
A magnetic dipole would be induced in the iron bar and the iron bar would try and align itself along the magnetic field lines because of the torque applied on it by the interaction of the induced dipole and the Earth’s magnetic field.
However since the torque which was applied on the iron bar would be very small the chances are that there would not be an alignment even if you waited a long time.
answered 1 hour ago
Farcher
47.4k33696
In the first paragraph, you seem to be assuming that the induced magnetization would be along the length of the bar, but I don't see any reason why that would be true. It could be in any random orientation relative to the bar's long dimension. The effect would then be that the bar would experience a torque that would tend to return it to whatever orientation it had when it was first able to be magnetized (e.g., at the time when the iron was first cooled below the Fermi temperature). You're then describing a bar that is magnetized, which is contrary to the question.
– Ben Crowell
1 min ago
add a comment |
A magnetic dipole would be induced in the iron bar and the iron bar would try and align itself along the magnetic field lines because of the torque applied on it by the interaction of the induced dipole and the Earth’s magnetic field.
However since the torque which was applied on the iron bar would be very small the chances are that there would not be an alignment even if you waited a long time.
answered 1 hour ago
Farcher
47.4k33696
In the first paragraph, you seem to be assuming that the induced magnetization would be along the length of the bar, but I don't see any reason why that would be true. It could be in any random orientation relative to the bar's long dimension. The effect would then be that the bar would experience a torque that would tend to return it to whatever orientation it had when it was first able to be magnetized (e.g., at the time when the iron was first cooled below the Fermi temperature). You're then describing a bar that is magnetized, which is contrary to the question.
– Ben Crowell
1 min ago
add a comment |
A magnetic dipole would be induced in the iron bar and the iron bar would try and align itself along the magnetic field lines because of the torque applied on it by the interaction of the induced dipole and the Earth’s magnetic field.
However since the torque which was applied on the iron bar would be very small the chances are that there would not be an alignment even if you waited a long time.
answered 1 hour ago
Farcher
47.4k33696
A magnetic dipole would be induced in the iron bar and the iron bar would try and align itself along the magnetic field lines because of the torque applied on it by the interaction of the induced dipole and the Earth’s magnetic field.
However since the torque which was applied on the iron bar would be very small the chances are that there would not be an alignment even if you waited a long time.
answered 1 hour ago
Farcher
47.4k33696
answered 1 hour ago
Farcher
47.4k33696
answered 1 hour ago
Farcher
47.4k33696
answered 1 hour ago
Farcher
47.4k33696
47.4k33696
In the first paragraph, you seem to be assuming that the induced magnetization would be along the length of the bar, but I don't see any reason why that would be true. It could be in any random orientation relative to the bar's long dimension. The effect would then be that the bar would experience a torque that would tend to return it to whatever orientation it had when it was first able to be magnetized (e.g., at the time when the iron was first cooled below the Fermi temperature). You're then describing a bar that is magnetized, which is contrary to the question.
– Ben Crowell
1 min ago
add a comment |
In the first paragraph, you seem to be assuming that the induced magnetization would be along the length of the bar, but I don't see any reason why that would be true. It could be in any random orientation relative to the bar's long dimension. The effect would then be that the bar would experience a torque that would tend to return it to whatever orientation it had when it was first able to be magnetized (e.g., at the time when the iron was first cooled below the Fermi temperature). You're then describing a bar that is magnetized, which is contrary to the question.
– Ben Crowell
1 min ago
In the first paragraph, you seem to be assuming that the induced magnetization would be along the length of the bar, but I don't see any reason why that would be true. It could be in any random orientation relative to the bar's long dimension. The effect would then be that the bar would experience a torque that would tend to return it to whatever orientation it had when it was first able to be magnetized (e.g., at the time when the iron was first cooled below the Fermi temperature). You're then describing a bar that is magnetized, which is contrary to the question.
– Ben Crowell
1 min ago
In the first paragraph, you seem to be assuming that the induced magnetization would be along the length of the bar, but I don't see any reason why that would be true. It could be in any random orientation relative to the bar's long dimension. The effect would then be that the bar would experience a torque that would tend to return it to whatever orientation it had when it was first able to be magnetized (e.g., at the time when the iron was first cooled below the Fermi temperature). You're then describing a bar that is magnetized, which is contrary to the question.
– Ben Crowell
1 min ago
add a comment |
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Why would you think “yes”?
– ZeroTheHero
2 hours ago
With the magnetic field of Earth no
– Alchimista
2 hours ago