DETERMINATION OF HORIZONTAL COMPONENT OF THE EARTH MAGNETIC FIELD INDUCTION

Task 1. Determine deviation angle at different values of current

1.1. Make an electric circuit (see figure 9, given in corresponding laboratory work of the textbook).

1.2. Set circular frame of galvanometer in magnetic meridian plane.

1.3. Close the circuit. Using rheostat R choose current values so as magnetic pointer deviates on angle j₁.

1.4. Change current values and repeat measurements according to item 1.3 4 (four) times. Enter the obtained results j₂, j₃, j₄ into table 1.

1.5. Change current direction flowing through galvanometer and repeat measurements according to items 1.3—1.4

Table 1

Task 2. Galvanometer constant determination

2.1. Determine galvanometer constant according to the formula:

Enter the results into table 2.

Table 2

2.2. Calculate galvanometer constant mean value according to the formula(n = 4):

2.3. Calculate galvanometer constant measured value deviation from mean value:

2.4. Calculate root-mean-square deviation according to the formula:

2.5. Determine the absolute error of galvanometer constant measurements according to the formula:

where the Student’s coefficient is t_St = 4,30 (n = 4 and a = 0,95).

2.6. Calculate fractional error according to the formula:

2.7. Write down the result in a form:

3. Determination of horizontal component of the Earth magnetic field induction.

3.1. Determine horizontal component of the Earth magnetic field induction according to the formula:

Enter the results into table 2.

3.2. Write down the result in a form:

____________ Тl,

Conclusions

The data of laboratory work fulfillment

Pass mark Signature

Mark of laboratory work defending Signature

questions to be admitted for doing laboratory work and its defending

1. Give the definition of magnetic field. What characteristics of magnetic field do you know?

2. What is intensity and induction of magnetic field characterized?

3. How experimentally can be determined that the Earth has magnetic field?

4. What is called South magnetic pole?

5. What is called North magnetic pole?

6. What is called magnetic meridian?

7. What is called magnetic descent?

8. How is magnetic descent determined?

9. What is called magnetic inclination?

10. How is magnetic inclination determined?

11. What quantities are called the Earth magnetism elements?

12. What are called isogonic line and isoclinal line?

13. What is magnetic anomaly region?

14. What is magnetic storm?

15. Formulate and write down Law of Bio and Savart.

16. Apply Law of Bio and Savart for magnetic field induction calculation in the center of circular ware with current.

17. The essence of the method of horizontal component of the Earth magnetic field induction determination.

18. Deduce the formula for horizontal component of the Earth magnetic field induction determination.

19. What is physical essence of tangent-galvanometer constant?

20. What is work order of laboratory work fulfillment?

Date: 2015-01-12; view: 1780