Electricity and Magnetism. (Mag Field)

In summary, the problem involves a circular wire loop with a resistance of 5.0 ohms and a time-dependent magnetic field. The magnetic flux through the loop at t = 2.0s can be calculated using the formula Φ = πa2Bcosθ, where B = 1.0 T sin (wt) [k hat]. The direction of the current induced in the loop at t = 2.0s can be determined using Faraday's law of induction and will flow in the direction opposite to the external magnetic field, which at t = 2.0s is in the direction of -k hat.
  • #1
Partap03
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Okay, I will be honest, this is a homework assignment. For that matter this is the last homework assignment which is very crucial to preparing for the final. But the problem is I have 2 more finals for which I need to study for. So if you can please help me out and give a detailed solution I will appreciate it. Thanks in advance.

A circular wire loop (radius a = 1m) has a resistance of 5.0 ohms and lies in the x-y plane. A spatially uniform but time-dependent magnetic field exists throughout the region. What is the magnetic flux passing through the loop at t = 2.0s? Show the direction of the current induced in the loop at t = 2.0s. B = 1.0 T sin(wt) [k hat]; w = 1.0 rad/s.
 
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  • #2
The magnetic flux through the loop at t = 2.0s is given by Φ = BAcosθ = πa2Bcosθ, where θ is the angle between the normal to the plane of the loop and the magnetic field. At t = 2.0s, the magnetic field is B = 1.0 T sin (wt) [k hat], so the magnetic flux through the loop is Φ = πa2Bcosθ = πa2(1.0 T sin (wt))cosθ. The direction of the current induced in the loop at t = 2.0s can be determined using Faraday's law of induction, which states that the rate of change of the magnetic flux through a loop is equal to the emf induced in the loop. Since the magnetic field is changing in time, an emf will be induced in the loop and a current will flow. The current will flow in the direction such that it produces a magnetic field that opposes the change in the external magnetic field. This means that the current will flow in the negative direction of the external magnetic field at t = 2.0s, which is in the direction of -k hat.
 
  • #3


I am happy to help you with this question about electricity and magnetism. First, let's review some important concepts. Electricity and magnetism are two fundamental forces of nature that are closely related. Electricity is the flow of electric charge, while magnetism is the force exerted by moving electric charges. When an electric current flows through a wire, it creates a magnetic field around the wire. Similarly, a changing magnetic field can induce an electric current in a wire.

Now, let's apply these concepts to the given scenario. We have a circular wire loop with a radius of 1m, and it has a resistance of 5.0 ohms. This means that when a current flows through the loop, there will be a voltage drop of 5.0 volts across the loop. Next, we are told that there is a spatially uniform but time-dependent magnetic field throughout the region. This means that the strength and direction of the magnetic field are the same at all points in space, but it varies with time. The magnetic field is given by B = 1.0 T sin(wt) [k hat], where B is the magnetic field vector, T is time, and w is the angular frequency.

To find the magnetic flux passing through the loop at t = 2.0s, we need to use the formula for magnetic flux, which is Φ = BAcosθ, where Φ is the magnetic flux, B is the magnetic field, A is the area of the loop, and θ is the angle between the magnetic field and the normal to the loop. In this case, the loop lies in the x-y plane, so the normal to the loop is in the z-direction. Therefore, the angle between the magnetic field and the normal is 90 degrees, and cos90 = 0. Plugging in the values, we get Φ = (1.0 T)(π1m2)(0) = 0 Wb.

Now, for the direction of the current induced in the loop at t = 2.0s, we can use Faraday's law of induction, which states that the induced voltage in a wire loop is proportional to the rate of change of magnetic flux through the loop. In other words, a changing magnetic field induces an electric current in the loop. In this case, the magnetic field is changing with time, so an electric current will be induced in the loop. The
 

FAQ: Electricity and Magnetism. (Mag Field)

What is the difference between electricity and magnetism?

Electricity and magnetism are two separate but related phenomena. Electricity is the flow of electric charge, while magnetism is the force exerted by moving electric charges. They are both part of the electromagnetic force, which is one of the four fundamental forces in nature.

How do magnets work?

Magnets work by creating a magnetic field, which is a force field that surrounds the magnet. This field is created by the alignment of tiny magnetic particles known as domains within the magnet. When another magnetic object enters this field, the domains within the magnet align with those in the object, creating a force that attracts or repels the two objects.

What is the relationship between electricity and magnetism?

Electricity and magnetism are closely related and can be observed together in the form of electromagnetic waves. When an electric current flows through a wire, it creates a magnetic field around the wire. Similarly, a changing magnetic field can induce an electric current in a wire. This relationship is described by Maxwell's equations.

How does the Earth's magnetic field protect us?

The Earth's magnetic field is created by the movement of molten iron in its core. This magnetic field extends into space and acts as a shield, deflecting harmful charged particles from the sun and other sources. This protects us from the damaging effects of solar radiation and helps to maintain a habitable environment on Earth.

What are some real-world applications of electricity and magnetism?

Electricity and magnetism have countless practical applications in our daily lives. Some common examples include generators, motors, transformers, and electromagnets, which are used in devices such as refrigerators, cars, and computers. Electromagnetic waves are also used in communication technologies such as radios, televisions, and cell phones.

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