What is the internal resistance of a galvanometer?

The resistance of a galvanometer is 100 Ω . A shunt of 5 Ω is connected to it to convert it into an ammeter.

What is the value of resistance of galvanometer?

The initial resistance of the galvanometer is equal to 50 ohms. The maximum value of the current that can be passed through a galvanometer is 0.002 A. The range of the reading of the current that this ammeter should show is 0 – 0.5 A.

What is resistance of coil of galvanometer?

The resistance RG of the coil of a pivoted-coil galvanometer is 9.36 Omega and a current of 0.0224 A causes it to deflected full scale. The only shunt available has a resistance of 0.0250 Omega.

Why internal resistance Cannot be measured by using a galvanometer?

The two reasons why a galvanometer cannot be used for measuring current are: The high resistance of galvanometer can disturb the original current flowing through the circuit. The high current present in the circuit can destroy the coil windings present in the galvanometer.

What is internal resistance of a cell?

Internal resistance refers to the opposition to the flow of current offered by the cells and batteries themselves resulting in the generation of heat. Internal resistance is measured in Ohms. The relationship between internal resistance (r) and emf (e) of cell s given by. e = I (r + R)

How can we convert galvanometer into ammeter?

A galvanometer is converted into an ammeter by connecting a low resistance in parallel with the galvanometer. This low resistance is called shunt resistance S. The scale is now calibrated in ampere and the range of ammeter depends on the values of the shunt resistance.

Why is the resistor RG placed in series with the galvanometer?

A large resistance R placed in series with a galvanometer G produces a voltmeter, the full-scale deflection of which depends on the choice of R. The larger the voltage to be measured, the larger R must be. (Note that r represents the internal resistance of the galvanometer.)

What is meant by internal resistance?

Internal Resistance is the resistance which is present within the battery that resists the current flow when connected to a circuit. Thus, it causes a voltage drop when current flows through it. It is the resistance provided by the electrolyte and electrodes which is present in a cell.

The internal resistance G of the galvanometer will thus depend on the wire used for the coil : material (copper, aluminum…), gauge (section of wire), length and temperature of operation (68 F). Let’s illustrate with an example : Coil : 100 turns of #32 (AWG) copper wire on a wound on a coil of diameter D=1.5 cm (assumed constant).

How do you use a galvanometer to measure voltage?

The galvanometer can be used to measure: a) the value of current in the circuit by connecting it in parallel to low resistance. b) the voltage by connecting it in series with high resistance. A galvanometer is converted into an ammeter by connecting it in parallel with a low resistance called shunt resistance.

What is a shunt in a galvanometer?

Now, the current flowing through the galvanometer is I/2 and remaining I/2 is by-passed by the resistance S connected across G. Because the current divides equally between G and S, therefore, The resistance S connected across a part of circuit to reduce current in that part only, is called the shunt.

What is the working principle of moving coil galvanometer?

The angle through which the coil is deflected due to the effect of the magnetic torque is proportional to the magnitude of current in the coil. The moving coil galvanometer is made up of a rectangular coil that has many turns and it is usually made of thinly insulated or fine copper wire that is wounded on a metallic frame.