Page 142 - Physics - XII
P. 142
tan tan N Y
m = 0
I 1 2RB H tan B
µ N
m = 0
2RB H
2 N 2 N
B = 4 Rm 10 Rm tanθ A C
7
0
H
Result
1. Experimental value of horizontal component of the X
Earth’s magnetic fi eld, B = _____ T Current I (ampere)
H
2. Theoretical value of horizontal component of the Earth’s Fig. 8.3: Graph showing relation between current
magnetic fi eld, B' = 0.32 × 10 T and defl ection of tangent galvanometer
–4
H
B B
3. Percentage error H H 100 ......%
B H
Precautions
1. The reversing key should be switched OFF when readings are not being taken.
2. The magnetic needle should swing freely in the horizontal plane.
3. The plane of the coil should be set in the magnetic meridian.
4. All the readings should be taken for defl ection in between 30° and 60°.
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