Faraday's Law of Induction and EMF

In summary, the conversation discusses a homework problem involving a coil and a solenoid. The coil has 15 turns and a radius of 10cm, while the solenoid has a radius of 2cm and 1x10^3 turns/m. The current in the solenoid is changing as I = (5A)sin(120t), and the goal is to find the induced emf in the coil as a function of time. The conversation also briefly touches on the magnetic field inside a solenoid and the difference between a coil and a solenoid. Finally, it suggests using the mutual inductance of the coil-solenoid system to solve the problem.
  • #1
stryker123
11
0

Homework Statement



A coil of 15 turns and radius 10cm surrounds a long solenoid of radius 2cm and 1x10^3 turns/m. The current in the solenoid changes as I = (5A)sin(120t). Find the induced emf in the 15-turn coil as a function of time.


Homework Equations



emf = -Nd[flux]/dt

d[flux] = int[B*dA]


The Attempt at a Solution



I have no idea how to start this. I tried doing some basic problems, but I just do not understand any of it.
 
Physics news on Phys.org
  • #2
What's the magnetic field inside a solenoid? What magnetic flux passes through the coil?
 
  • #3
Never mind, I posted my own thread.
 
Last edited:
  • #4
What is the difference between a coil and a solenoid? (I'm asking the question seriously).
 
  • #5
cepheid said:
What is the difference between a coil and a solenoid? (I'm asking the question seriously).

For this problem:

COIL
mult_layer_air_coil.png


Solenoid
solenoid.jpg


In general people may (and will) say "coil" for the second case too.
 
  • #6
Did you consider using the mutual inductance of the coil-solenoid system?

I have a theory question for you that might help to get you started on this problem:

What special characteristic of Mutual inductance helps us to quickly and easily solve problems like this?

Good luck,

Wynand.
 

1. What is Faraday's Law of Induction?

Faraday's Law of Induction states that when there is a change in the magnetic field passing through a conductor, an electromotive force (EMF) is induced in the conductor, which then causes an electric current to flow.

2. How is Faraday's Law of Induction related to electromagnetic induction?

Faraday's Law of Induction is a fundamental principle of electromagnetic induction, which is the process of generating an electromotive force by moving a conductor through a magnetic field or changing the magnetic field passing through a stationary conductor.

3. What is the formula for calculating the magnitude of induced EMF?

The formula is EMF = -N x ΔΦ/Δt, where N is the number of turns in the coil, ΔΦ is the change in magnetic flux, and Δt is the change in time.

4. What are some real-world applications of Faraday's Law of Induction?

Some common applications include generators, transformers, and electric motors. It is also used in devices such as induction cooktops and wireless chargers.

5. How does Lenz's Law relate to Faraday's Law of Induction?

Lenz's Law is a consequence of Faraday's Law of Induction. It states that the direction of the induced current will always oppose the change that caused it. This is why when a magnet is moved through a coil, the induced current creates a magnetic field that opposes the motion of the magnet.

Similar threads

Replies
17
Views
1K
Replies
6
Views
3K
  • Introductory Physics Homework Help
Replies
3
Views
100
  • Electrical Engineering
Replies
1
Views
774
Replies
11
Views
2K
  • Introductory Physics Homework Help
Replies
7
Views
281
Replies
27
Views
1K
  • Introductory Physics Homework Help
Replies
6
Views
1K
  • Electromagnetism
Replies
6
Views
723
  • Electromagnetism
Replies
4
Views
1K
Back
Top