My teacher hasnt been in and Im trying to self teach this topic. Can

[KatieKangaroo]

My teacher hasnt been in and I am trying to self teach this topic. Can anyone help me with this question, its probably quite simple but I am really stuck
A flat circular coil of mean diameter 3.0cm has 500 turns and is situated so that the plane of the coil is perpendicular to a uniform magnetic field of flux density 20mT. The intensity of the field is reduced to zero and then increased to 20mT in the opposite direction at the same steady rate throughout. Calculate the EMF induced in the coil if the whole operation takes 60ms.
Thanks in advance for any help.

Also: if the EMF is at its peak, is the current also at its peak?

 

[El Hombre Invisible]

My teacher hasnt been in and I am trying to self teach this topic. Can anyone help me with this question, its probably quite simple but I am really stuck
A flat circular coil of mean diameter 3.0cm has 500 turns and is situated so that the plane of the coil is perpendicular to a uniform magnetic field of flux density 20mT. The intensity of the field is reduced to zero and then increased to 20mT in the opposite direction at the same steady rate throughout. Calculate the EMF induced in the coil if the whole operation takes 60ms.

Just use Faraday's law:

[tex]EMF = -N\frac{\Delta\phi}{\Delta t}[/tex]

You have the magnetic flux density, so flux = density * area. You know the change in magnetic flux (+20mT to -20mT) and you know how long it took (60 ms). N is the number of coils.

Also: if the EMF is at its peak, is the current also at its peak?

Ohm's law is V = iR, so yes: voltage (EMF) is proportional to current.

 

[quicknote]

I understand your frustration with not having a teacher present to guide you through this topic. However, self-teaching can also be a valuable skill to have in the scientific field. Let's start by breaking down the problem and identifying the key information and equations we will need to solve it.

First, we are given the dimensions and characteristics of a flat circular coil, including its diameter, number of turns, and orientation in a uniform magnetic field. This information will be important in calculating the magnetic flux and induced EMF.

Next, we are told that the magnetic field is changing at a steady rate, from 0 to 20mT and then back to 0, over a period of 60ms. This will be important in determining the rate of change of flux and the time interval over which it occurs.

To solve this problem, we will need to use Faraday's Law of Electromagnetic Induction, which states that the induced EMF (ε) is equal to the rate of change of magnetic flux (Φ) over time (t): ε = -dΦ/dt. We can also use the equation for magnetic flux, Φ = BAcosθ, where B is the magnetic field strength, A is the area of the coil, and θ is the angle between the magnetic field and the plane of the coil.

Using these equations, we can first calculate the initial and final magnetic flux values, as well as the rate of change of flux. Then, we can plug these values into Faraday's Law to solve for the induced EMF.

As for your second question, whether the EMF and current are at their peak simultaneously, the answer is yes. According to Ohm's Law, current (I) is equal to the voltage (V) divided by the resistance (R), or I = V/R. Since the resistance of the coil remains constant, an increase in EMF will result in an increase in current. Therefore, when the EMF is at its peak, the current will also be at its peak.

I hope this explanation helps you to better understand the problem and how to approach it. Remember to always use the information given and relevant equations to guide your problem-solving process. And don't be afraid to ask for help or consult additional resources when needed. Good luck!