A coil with turns given magnetic field, time find the emf induced in the coil

In summary, the total magnetic flux through the coil before it is rotated is 1.9*10^-5 WB, and the total magnetic flux after it is rotated is 0 WB. The average emf induced in the coil is 3.28*10^-8 V.
  • #1
sonrie
35
0
A coil with 240 turns enclosing an area of 13.7 cm^2 is rotated in a time interval of 3.70×10^-2 s from a position where its plane is perpendicular to the Earth's magnetic field to one where its plane is parallel to the field. The Earth's magnetic field at the lab location is 5.9×10−5 T .

What is the total magnetic flux through the coil before it is rotated?
I found this answer its 1.9*10^-5 WB.

What is the total magnetic flux through the coil after it is rotated?
I found this answer its 0 WB.

What is the average emf induced in the coil?

I'm having trouble getting the right answer! I get 1.27*10^-7 but its wrong! Help Please!
 
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  • #2
sonrie said:
What is the total magnetic flux through the coil before it is rotated?
I found this answer its 1.9*10^-5 WB.
Double check the exponents in this answer.

What is the total magnetic flux through the coil after it is rotated?
I found this answer its 0 WB.
Good.

What is the average emf induced in the coil?

I'm having trouble getting the right answer! I get 1.27*10^-7 but its wrong!
How did you get this?
 
  • #3
the equation is emf = -N BA/T

-240 5.9*10^-5*.137/5.9*10^-5=3.28*10^-9 its still wrong
 
  • #4
sonrie said:
the equation is emf = -N BA/T

-240 5.9*10^-5*.137/5.9*10^-5=3.28*10^-9 its still wrong
You have the correct formula, but you need to redo the calculation more carefully:
(1) You have the incorrect area. (Note that 1 cm^2 [itex]= 10^{-4}[/itex] m^2.)
(2) Divide by the time interval.
 
  • #5
Thank you!
 

1. How does the number of turns in a coil affect the induced emf?

The induced emf in a coil is directly proportional to the number of turns in the coil. This means that the more turns a coil has, the higher the induced emf will be.

2. What is the relationship between magnetic field strength and induced emf in a coil?

The induced emf in a coil is directly proportional to the strength of the magnetic field passing through it. This means that a stronger magnetic field will result in a higher induced emf.

3. How does the time interval affect the induced emf in a coil?

The induced emf in a coil is directly proportional to the change in magnetic field over time. This means that a longer time interval will result in a higher induced emf, while a shorter time interval will result in a lower induced emf.

4. What is the formula for calculating the induced emf in a coil?

The formula for calculating the induced emf in a coil is: E = -N(dΦ/dt), where E is the induced emf, N is the number of turns in the coil, and (dΦ/dt) is the rate of change of magnetic flux.

5. Can the direction of the induced emf be reversed?

Yes, the direction of the induced emf in a coil can be reversed by changing the direction of the magnetic field or by changing the direction of the movement of the coil. This is known as Faraday's law of electromagnetic induction.

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