Question

This is my experiment about Earth magnetic field induction by tangensgalvonometer. I must additional conclusion for my experimental values and Bo=1.68x10^-5 T.

Could you compare Bo=1.68x10^-5 and my experimental values. experiment did same city which is Bo=1.68x10^-5

I need conclusion about this case. thank you.

Results: Bo (1-1 )-7.66x10 Be(l 2-0107 Be (1-3 )-1.72x10 · Be (1-3, 2 )" f,79x16 Bo (Rī9小1.GC-er「 Measurement of the horizontal component of Earth's magnetic field induction by tangensgalvanometer In each point the Earth's magnetic field is directed in any defined angle with respect to the horizontal plane and meridian, therefore the induction vector of Earth's magnetic field usually is splitted into two components: horizontal and vertical one. The magnetic arrow with vertical axis then will oriented by horizontal component of magnetic field. This property is used in devices called tangensgalvenometres (TG). By TG is possible to define either the horizontal component of Earth magnetic field Bo, or to measure current, if the value of this is known at any specific place. For Riga Bo= 0.168 x10-4 T TG consists of vertically placed loop with one or more tums of wire (1 on fig.1). In the center of this loop the magnetic arrow (2 on fig.1) or compass is placed which is able to turn around the vertical axis in horizontal plane. If there is no current in TG, than arrow is positioned along the meridian of the Earth magnetic field. The loops of wire should be oriented also in this direction. If the current flows through the wire, the induction vector Bi of generated Figl.Te magnetic field is perpendicular both to the wire plane and Earth's tangensgalvanometer The schematic view of the magnetic field vector Bo Vectors of discussed fields are shown on fig.2 (top view). Bre Under the action of these two fields magnetic arrow will be oriented along the resultant field Bre and is deflected on angle ф from the original direction. The value of this angle can be derived from following equation (see Fig.2): The plane of windings Fig.2. The scheme of Earth's and current magnetic fields inside TG (top view) The induction B of current loop magnetic field in the center of it according to the Bio-Sawart law is: 2R where B- induction of magnetic field (T); - magnetic permeability constant (1,2566x106 H/m); I- current (A); the number of turns; r-the radius of the loop (m). From (2) the current I can be expressed and, using (1), recorded as ton 2Bo R Om 20A s a TG constant. From last expression we have got 0 2R and 2Rig that is, the horizontal component of the Earth's magnetic field induction Bo can be defined, if the current in the TG is measured, or the constant of the TG is known. If the constant k of the TG is known, than the TG can be used also for current measurement. To calculate k Bo must be given. The constant can be defined also experimentally, by measuring of the angle of deflection of magnetic arrow and corresponding current Fig.3. Electrical scheme for definition of the horizontal component of Earth's magnetic field induction by using the tangensgalvanometer Laboratorijas darbs 2.5 The scheme of used circuit is shown on Fig.3. Before the beginning of measurement the loop of wire should be placed parallel to the meridian of Earth's magnetic field. The magnetic arrow should be placed very precisely in the center of the TG. The current in the loop is measured by ammeter A The six-pole switch S is used to change the direction of the current on the opposite one. For precise definition of the angle φ, current of both directions is used and corresponding angles of deflection are defined (ф 1 and ф 2). The mean value of ф should be taken for calculations: 91 + 92 Measurements should be performed by different currents, which can be changed by variable resistor R, and Bo should be calculated by using (5) The readings of the TG can be disturbed by neighbourhood magnetic field, therefore it should be placed as far as possible from other parts of the circuit (resistor, source of current), connecting wires and ferromagnetic objects Possible appointments for the work. . To determine the horizontal component of the Earth's magnetic field induction at specific place. 2. To construct the graph tgp fl) and define the constant of the tangensgalvanometer.

Answer 1

The tangent galvanometer was used to find out the horizontal intensity of the earth's magnetic field.Using the tangent galvanometer experiment,Bav was found to be 1.69*10^(-5) while the given value is B0=1.68*10^(-5) which shows only a very small error value(error=.005%).The galvanometer constant was also found out by plotting a graph between tan phi and I which happens to be a straight line.