Galvanometer to ammeter/voltmeter

  • Thread starter Dr. Science
  • Start date
  • Tags
    Galvanometer
In summary, to convert a galvanometer to an ammeter reading 20mA full scale, the shunt resistance should be 0.641ohms. To convert it to a voltmeter reading 500mV full scale, the series resistance should be 975ohms.
  • #1
Dr. Science
31
0

Homework Statement



The resistance of a galvanometer coil is 25ohms and the current required for full scale deflection is 500μA.
a) explain how to convert the galvanometer to an ammeter reading 20mA full scale, and compute the shunt resistance
b) explain how to convert the galvanometer to a voltmeter reading 500mV full scale, compute the series resistance

Homework Equations



V=IR
IfsRG= (Ia-Ifs)Rsh
Rsh=(RGIfs)/(Ia-Ifs)

The Attempt at a Solution

RG=25ohms

a)
does Ifs=0.02 or 0.0005A

0.0005A * 25ohms = ( 0.02A- 0.0005A) Rsh ??
Rsh=0.641

b)
 
Last edited:
Physics news on Phys.org
  • #2
Your value for (a) looks okay. How will you approach (b)?
 
  • #3
idk VV=Ifs(Rsh+Rh)
 
  • #4
(0.5/0.0005) -25 = 975 ?
 
  • #5
Looks good.
 
  • #6
cool beans
 

Related to Galvanometer to ammeter/voltmeter

What is a galvanometer?

A galvanometer is an instrument used to measure small electrical currents. It works by converting electrical current into mechanical movement, which is then displayed on a scale.

How does a galvanometer work?

A galvanometer works by using a coil of wire and a magnet. When an electrical current flows through the coil, it creates a magnetic field which interacts with the magnet, causing the coil to move. The amount of movement is proportional to the strength of the current.

What is the difference between a galvanometer and an ammeter/voltmeter?

A galvanometer measures small currents, while an ammeter measures larger currents and a voltmeter measures voltage. Ammeters and voltmeters are essentially modified versions of a galvanometer with additional components to measure larger currents and voltage.

How do you convert a galvanometer into an ammeter/voltmeter?

To convert a galvanometer into an ammeter, a low resistance shunt is added in parallel with the galvanometer. This allows the majority of the current to flow through the shunt, while only a small portion flows through the galvanometer, which can then be used to measure the larger current. To convert a galvanometer into a voltmeter, a high resistance resistor is added in series with the galvanometer. This limits the current flowing through the galvanometer, allowing it to measure the voltage drop across the resistor and display the voltage on a scale.

What are the limitations of using a galvanometer as an ammeter/voltmeter?

The main limitation of using a galvanometer as an ammeter or voltmeter is that it can only measure small currents. If the current being measured is too large, it can damage the galvanometer. Additionally, a galvanometer has a limited range and may not be accurate for measuring very small or very large currents or voltages.

Similar threads

What is the effect of a shunt on the sensitivity of a moving coil galvanometer?
    • Introductory Physics Homework Help
Replies
13
Views
2K
A Galvanometer of Coil Resistance 50 Ω Deflects Full Scale....
    • Introductory Physics Homework Help
Replies
2
Views
2K
Value of resistor for full scale deflection with 10A
    • Introductory Physics Homework Help
Replies
1
Views
1K
Voltage that would produce full-scale deflection of a meter
    • Introductory Physics Homework Help
Replies
18
Views
6K
Finding the maximum value of current
    • Introductory Physics Homework Help
Replies
5
Views
3K
The REAL difference between a Galvanometer and an Ammeter
    • Electrical Engineering
Replies
6
Views
1K
Converting a galvanometer to ammeter and voltmeter.
    • Introductory Physics Homework Help
Replies
5
Views
3K
Ammeters and voltmeters in series
    • Introductory Physics Homework Help
Replies
10
Views
2K
Multirange Ammeter magnitudes homework
    • Introductory Physics Homework Help
Replies
2
Views
2K
The sensitivity of the galvanometer
    • Introductory Physics Homework Help
Replies
3
Views
3K

Hot Threads

Recent Insights

Back
Top