Lab 4

    Following are the steps for finding the value of  (muo) -

    I.        Find the average value of   (theta)  --   (theta)av   =   [(theta)   + (theta)rev ]/2

    II.      Find    Bc   using the equation     Bc  =  Be  tan (theta)av  , where   Be   is the earth's
               magnetic  field.

    III.    Plot the values of   Bc    found above with current   I   on the x-axis  and find the
              slope of  the three lines.

    IV.     Plot the values of slopes    Mn   you found above against    n .   You had to plot the
               values found experimentally and not the theoretical values.

    V.       Find the slope    m    of line of    Mn   vs.    n  .  From this slope, you get the  value of
               (muo)  as follows -
                                     m =  (muo) /2R           ==>       (muo)  =  2mR .
               Compare this   (muo)expt   with    (muo)theo  .

    VI.      Units of various quantities --
                        Bc   and    Be     in  T  i.e.  Tesla,
                        Mn    in    T/A     i.e.    Tesla/Amperes,
                         m      in    T/A ,
                         (muo)   in   (T/A)m   =
 
    VII.     Field lines should not cross each other.

    VIII.    Which object has stronger mag. field ?  The way you infer this is .....
 
 

    IX.       The field of the rheostat coil was most similar to  ...........
 
 
 

    X.        Angle of inclination of the compass needle ......
 
 

    XI.      derivation of the equation   Bc  =  Be  tan (theta)av    ----
 
 

                                (I'll have the answers soon......)