Comparing the Magnetic Moment of Two Bar Magnets using Equal Distance and Null Deflection Methods with a Deflection Magnetometer in Tan

Deflection magnetometer - tan A, tan-B and verification of inverse square law
Aim :
To compare the magnetic moment of the two bar magnets using equal distance method and null deflection methods using a deflection magnetometer in tan - A position

Apparatus :
Deflection magnetometer, bar magnets

Formula:
(a) Equal distance method
M1 / M2 = tan(θ1) / tan(θ2) where tan(θ1) and tan(θ2) are the average of deflections due to bar magnets M1 and M2 respectively (b) Null deflection magnetometer
M1 / M2 = d13 / d23 where d1 is the distance of M1 and d2 is the average of the distances of M2

Equal distance method ( Tan – A )
S.No.distance

tan(θ) M1/M2

α7

α8

55

54

56

57

55

54

53

56 55.00

1.39

57

56

58

59

55

56

57

56 56.75

1.52

51

50

52

51

53

51

50

52 51.25

1.24

52

53

53

54

52

53

51

53 52.62

1.30

M1

20

α6

45

47

45

46

47

44

46

45 46.75

1.06

M2

3

α5

M1

18

α4

M2

2

α3

M1

16

α2

M2

1

α1

49

48

47

49

48

46

49

47 47.87

1.10

θ

0.96

0.94

0.96

Null deflection method ( Tan – A )
S.No.

d1

x1

x2

x3

x4

d2

d13/d23

1

16

16.2

16.1

16.2

16.1

16.23

0.97

2

18

18.2

18.3

18.3

18.2

18.25

0.96

Equal distance method ( Tan - B )
S.No.distance

tan(θ) M1/M2

α5

α6

α7

α8

θ

45

42

48

45

47

46

42

43

44.75

0.99

49

48

48

47

49

46

45

48

47.5

1.09

M1

16

α4

35

36

34

35

38

36

37

35

35.75

0.71

M2

2

α3

M1

14

α2

M2

1

α1

37

38

37

39

38

37

38

36

37.81

0.77

0.90

0.92

Null deflection method ( Tan - B )
S.No.

d1

x1

x2

x3

x4

d2

d13/d23

1

14

14.4

14.3

14.5

14.6

14.44

0.91