Question regarding ammeters & galvanometers

[dazed99]

Homework Statement

The question I'm having trouble with is: An ammeter has a sensitivity of 10000 Ohm/V. What current passing through the galvanometer produces full-scale deflection?

Homework Equations

No idea! Only equation somewhat relevant I've seen is (Ir)(Rsh) = (Ig)r

The Attempt at a Solution

I think I'm missing information. How can I figure this out with just the 10000 Ohm/V provided? Don't I need more to work with?

 

[anathema]

Hello,

To solve this problem, you will need to use the equation you mentioned: (Ir)(Rsh) = (Ig)r. This equation relates the current passing through the galvanometer (Ig) to the current passing through the shunt resistor (Ir), the resistance of the shunt resistor (Rsh), and the resistance of the galvanometer (r).

In this case, the sensitivity of the ammeter (10000 Ohm/V) is equal to the resistance of the shunt resistor (Rsh). This means that when 1 V is applied to the ammeter, 10000 Ohm of resistance is added to the circuit.

To find the current that produces full-scale deflection, you will need to set Ig equal to the maximum current that the galvanometer can handle (usually indicated on the instrument). Then, solve for Ir using the equation above. This will give you the current that needs to pass through the shunt resistor in order to produce full-scale deflection on the galvanometer.

I hope this helps! Let me know if you have any further questions.

 

[Moetasim]

I would suggest that you first determine the type of galvanometer being used. Different types of galvanometers have different sensitivities and therefore, require different equations to determine full-scale deflection. Once you have determined the type of galvanometer being used, you can then use the appropriate equation to solve for the current needed to produce full-scale deflection.

Additionally, it may be helpful to have more information about the circuit in which the ammeter and galvanometer are being used. This could include the resistance of the circuit, the voltage being applied, and the type of current (AC or DC). All of these factors can affect the calculation of the current needed for full-scale deflection.

In general, the equation you mentioned (Ir)(Rsh) = (Ig)r is used for a shunt-type galvanometer, where Ir is the current passing through the shunt resistor, Rsh is the shunt resistor's resistance, Ig is the current passing through the galvanometer, and r is the galvanometer's sensitivity. If this is the type of galvanometer being used, you may need to use this equation along with the given sensitivity of the ammeter to solve for the current needed for full-scale deflection.

Overall, it is important to have all the necessary information and to use the appropriate equations when solving problems involving ammeters and galvanometers. If you are still unsure, I would recommend consulting with a teacher or tutor for further assistance.