Tangent Galvanometer

The tangent galvanometer refers to a device that facilitates the measurement of current. It acts in accordance with the principle of tangent law. Here, a magnetic needle is suspended at a point where the crossing of two fields takes place at right angles to each other. Specifically, this point is where these fields shall come to a state of rest in the direction of the resultant. The tangent galvanometer has a vertical coil of wire. Towards the centre of it is a horizontal magnetic needle. The current, whose measurement is to take place, passes via the coil.  Let’s now discuss more about tangent galvanometers. Here, we shall take a look at who invented the tangent galvanometer.

Understanding the Working of Tangent Galvanometer

The tangent galvanometer helps in the measurement of electric current. This instrument is able to measure the following:

·  The presence of the currents

·  The direction of the currents

·  The power of the currents

Tangent galvanometers have the following:

·  A vertical copper wire

·  A circular frame

·  A compass needle in the middle

The copper wire is coiled around the frame. Whenever an electrical current takes place, the compass needle will respond to the magnetic field.

Over the years, the Tangent galvanometers have been designed in various forms. The advanced forms utilise beams of light for determining the measurements. Some forms are useful in measuring the Earth’s magnetic field in a significantly accurate manner.

Usually, the tangent galvanometers are placed on a flat surface. Moreover, in such a setting, the compass is used to align the coil in a north to south manner. The needle is then lined up with the coil’s direction. This way, when there is an application of current; one can measure the angle the needle turns.

The rotation of the compass needle can take place in any horizontal direction. Also, there are four quadrants on a scale on the device. Each of these quadrants equals a quarter of a circle. One can read the scale by analysing the pointer that is attached to the needle at a 90-degree angle.

Who Invented Tangent Galvanometer?

The earliest form of the electromagnetic galvanometer was invented by Johann Schweigger in the year 1820. However, in 1834, J.J. Nervander designed the tangent galvanometer, which was more sensitive than the electromagnetic galvanometer. This led to a massive improvement in the electric current measurement. Now, even very precise measurements of electric current can be carried out with great efficiency.

Nervander had ensured inventive coiling arrangements in his invention. This allowed him to prove the validity of an important law by using the tangent bussol. According to this law, the deviation angle tangent of the tangent-bussol needle is proportional to the flowing electric current.

Utilisation of the tangent law opened a suitable path for the measurement and comparison of the currents. The reason for the increased sensitivity was due to the uniformity of the current-created magnetic field over the coils’ cylindrical volume. This made possible the utilisation of a long magnetic needle.

Uses of Tangent Galvanometer

Below are the uses of tangent galvanometer:

·  It helps in investigating the magnetic field at the central portion of a loop of wire that carries current.

·  Facilitates the verification of the right-hand rule for the field inside the current loop.

·  It makes possible the investigation of the vector nature of magnetic fields and it helps in understanding how they add vectorially.

·  One can easily verify the relationship between the magnetic field inside the current loop, the current itself, and the number of turns with a tangent galvanometer. Here, the Earth’s field is used as a reference.

·  It helps in the determination of the accurate strength of the magnetic field of the Earth.

Conclusion

The tangent galvanometer  refers to a device that facilitates the measurement of current according to the principle of tangent law. It helps in the measurement of the presence, direction, and power of the currents. These instruments have the following main parts- a vertical copper wire, a circular frame, and a compass needle in the middle. In the year 1834, J.J. Nervander designed this instrument. It was more sensitive than the electromagnetic galvanometer. There are various uses of tangent galvanometer pertaining to electric current and magnetic field.