PreLab –The Magnetic Fields               Name:

 

1.     (1)  What is a solenoid (10 words or less) and list two more examples of solenoids in common use beyond the below example.

 

 

 

 

 

 

 

      a.   electric car door lock

b.

c.

    Internet search (or lecture book)

  1. (1) The field sensor (or a search coil) used in this lab is
    1. a RC Circuit.
    2. an Inductor.
    3. a Capacitor.
    4. none of the above

 

 

 

            Internet search:  Beyond DC circuits

            Hint:  look up ELI the ICE man

                        (emf à electromotive force, Voltage)

  1. (½) How is the phase between the voltage and the current related in the above field sensor?
    1. They are in phase
    2. Current leads the Voltage by 90°
    3. Voltage leads the Current by 90°
    4. Current leads the Voltage by 180°

 

 

4.     Write the formula for the magnetic field

a.     (1) According to Biot-Savart law when the length of the coil is small compared to its radius.

 

 

 

 

 

 

 

 

 

Note:  in the lab, voltage is directly proportional to magnetic field strength, thus log (B) vs log (x) will be equal to log (V) vs log (x).

 

5.     (1 ½)  Calculate the slope for the graph log B vs log x as in Step 5, please note the last portion of Step 5.                 (Linefit)

 

slope:

 

y-int:

 

x-int:

 

 

(½)  Question:  Did you have to eliminate some of the data while plotting and did the slope of the remaining data indicate that the length is large compared to the radius.  If yes, why?

 

x

(cm)

 B

(Gauss)

 

log(x)

 

log(B)

2.0

15.32

 

 

5.0

4.981

 

 

7.0

2.484

 

 

10

1.029

 

 

13

.482

 

 

16

.264

 

 

19

.149

 

 

 

fyi, 100 Gauss = 1 Tesla