13-02-2013, 12:39 PM
Tangent Galvanometer
Tangent.docx (Size: 207.45 KB / Downloads: 89)
Aim:
1. To determine the reduction factor of the given tangent galvanometer (K).
2. To find out the horizontal component of earth’s magnetic field (Bh).
Apparatus:
Tangent galvanometer (TG), commutator ©, rheostat ®, battery (E), ammeter (A), key (K) etc
Principle:
When a bar magnet is suspended in two Magnetic fields B and Bh, it comes to rest making an angle θ with the direction of Bh.
Theory:
Tangent galvanometer is an early measuring instrument for small electric currents. It consists of a coil of insulated copper wire wound on a circular nonmagnetic frame. Its working is based on the principle of the tangent law of magnetism. When a current is passed through the circular coil, a magnetic field (B) is produced at the center of the coil in a direction perpendicular to the plane of the coil. The TG is arranged in such a way that the horizontal component of earth’s magnetic field (Bh) is in the direction of the plane of the coil. The magnetic needle is then under the action of two mutually perpendicular fields. If θ is the deflection of the needle, then according to tangent law