Investigate, using a search coil and oscilloscope, the effect on magnetic flux density of varying the angle between a search coil and magnetic field direction Flashcards Preview

A2 Physics F > Investigate, using a search coil and oscilloscope, the effect on magnetic flux density of varying the angle between a search coil and magnetic field direction > Flashcards

Flashcards in Investigate, using a search coil and oscilloscope, the effect on magnetic flux density of varying the angle between a search coil and magnetic field direction Deck (11):
1

What is a search coil?

  • small flat coil a made from 500 - 2000 turns of insulated wire mounted on a handle

2

How is an emf induced in the coil?

  • placed inside a varying magnetic field

3

How does the flux through the coil constantly change?

  • connected to alternating power supply

4

Why is it connected to an oscilliscope?

  • record the induced emf

 

 

5

What happens wghen the field is varying at a constant rate?

  • the amplitude of the induced emf will be directly proportional to the amplitude of the magnetic flux density of the field

 

 

6

How is the equipment set up?

  • search coil clamped with its face perpendicular to the flux lines produiced by the circular coil
    • θ = 0 
  • as cos0 = 1 
    • max flux linkage and max induced emf in search coil

 

7

Why is the time base of the oscilloscope switched off>

  • induced emf displayed as vertical line
  • measurement taken of this line

 

 

8

How is amplitude calculated from the length of line

 

 

  • half the length of the line
  • and by referring to the y-gain setting on the oscilliscope

9

How is the experiment done from there?

  • coil rotated and induced emf measured at each angle
    • 10 degrees each time
    • emf will decrease
  • measure angle using potractor

 

 

10

What is the safety concern in this experiment?>

  • coil taking relatively large current, it will heat up 
  • do not leave on for longer than necessary

11

why does emf decreaSE?

  • the search coil is cutting fewer flux l;ines as the component of the magnetic field perpendicular is lower
  • this means that the magnetic flux linkage is lower