Tag Info

What area should be chosen for finding EMF induced when only magnetic field $B$ is changing?

But what if we need to find EMF induced through an isolated conductor such as a rod[?] We can define the emf induced by a changing magnetic field in a wire (or rod) with the equation: \mathscr{E}_{\...
• 3,161

Why Is an Inhomogenous Magnetic Field Used in the Stern Gerlach Experiment?

Just some ideas to complement what is mentioned at https://physics.stackexchange.com/a/596531/31891 that dipoles experience zero net force in a homongenous field: to see why this is true, start by ...

Emf in stationary conductor located in a uniform magnetic field, when the source of this field moves relative to the conductor

First of all, the magnetic field is not changing inside the conductor, because it is constant in magnitude and direction inside it, throught the motion you considered. For analysing this case, you can ...

Energy density due to magnetization and magnetic field

The field energy due to a single PERMANENTLY magnetized sphere of magnetization per unit volume $\bf{M}$ at a location in an external magnetic field where, absent the sphere, the value of the flux ...
• 880

What are the main sources of magnetic fields?

The old answer below misses the mark. I am tryin again. New Answer Classically speaking, electric fields are generated by electric charges and changing magnetic fields. Magnetic fields are generated ...
• 14.9k

What are the main sources of magnetic fields?

The main sources of magnetic fields are: Moving Electric Charges: A magnetic field is generated by electric charges in motion, such as in a current-carrying wire. Permanent Magnets: These materials, ...
Accepted

Are the accelerated charges the real reason for the magnetic induction?

Yes, this explanation works in cases where the EMF is due to electric current in a stationary circuit changing in time. Magnetic flux is proportional to current, so according to the Faraday law, ...
• 39.8k

Should electrons as tiny magnets, stick to a permanent magnet if in appropriate conditions?

The electrons do have an intrinsic magnetic moment due to their spin. In order for the permanent magnet to exert an attractive force on them, there usually needs to be a magnetic field gradient as in ...
• 51

Why does the tension change instead of the speed of this object undergoing circular motion?

Since the magnetic force is always perpendicular to the direction of motion of the particle, the force can only induce a centripetal acceleration. Or in simpler terms, the force can only change the ...
Accepted

Why does the tension change instead of the speed of this object undergoing circular motion?

For the speed to change, there must be a force acting in the direction of motion. But both the magnetic force and the tension force always act perpendicular to motion. There is no force that can ...
• 10.1k
Accepted

What is the electric field inside an inductor?

You can find the electric field inside the inductor using Faraday's Law. The magnetic field inside an ideal inductor is uniform, pointing in the direction along the axis of the inductor. The Faraday ...

Induced emf and coil winding direction

Suppose a coil with a clockwise winding, perpendicular to the ground. Let's have a constant current flowing with direction downward. The magnetic field inside the coil, according to the right hand ...
• 16.9k
1 vote
Accepted

How many times do you need to drop a magnet for it to lose it's power?

This is exactly how magnets work: you can magnetize a a soft iron rod by pointing one end at the north pole and smacking the other end with a hammer. If you then reverse the rod and smack it again you ...
• 96.8k

How many times do you need to drop a magnet for it to lose it's power?

That's not how magnets work. Magnets work because of the alignment of electron magnetic fields throughout the metal - there's no power inside keeping it going. Electromagnets do require power, but ...

Changing the magnetic field of earth

In 2022, the total energy consumption of humanity was estimated at 24,398 terawatt-hours (about 24.398 terawatts continuously for the whole year), while the Earth's magnetic field's total energy is ...
• 1,930

Find the leading $1/L$ corrections to the magnetic field for a finite solenoid of length $L$

Let $S_L$ be a solenoid of length $L$ whose center is at the origin, and $S$ an infinite solenoid. The difference $S - S_L$, call it $S_{\overline{L}}$, is a pair of half-infinite solenoids: the parts ...
• 6,699

Why do passive materials impact magnetic field?

By "passive materials" I assume you mean paramagnetic materials. Although these materials will not support their own intrinsic magnetic field, they will still react to an external magnetic ...
• 57.7k
1 vote

Solve for the shape and curvature of Earth's magnetic field

It's not something you solve. It's something you measure: https://www.ncei.noaa.gov/products/world-magnetic-model Last time I used it, briefly, it was only out to degree 7 (in contrast to gravity, ...
• 37.1k

How to find the magnetization of a neodymium magnet?

Discounting horseshoes and other weird shapes, most conventional magnets can be approximated by dipoles. I think what you are asking is "how can I calculate the effective dipole moment of a ...
• 880

Violation of work-energy theorem (WET) in deriving potential energy (PE) of current-carrying ring in a uniform magnetic field

I am not much of an expert in electromagnetism but the entire reason behind my answer is that you got the WET wrong. I know that many textbooks do not write it properly, so it's not your fault. The ...
1 vote

Violation of work-energy theorem (WET) in deriving potential energy (PE) of current-carrying ring in a uniform magnetic field

Is it not violation of work-energy theorem (WET) as Work done by external agent is the change in Kinetic Energy and not change in potential energy (PE)? In the work energy theorem the work is net ...
• 76k
In any simply connected region with no current (see note 1) or Maxwell's displacement current, $\vec{B}$ is conservative. Since it is also solenoidal, this entails that it satisfies Laplace's Equation....