How can a galvanometer be converted into a ammeter and voltmeter?plz explain?

3 years ago

Share

Answers : (1)

                                        

CONVERSION OF GALVANOMETER 
INTO AMMETER


  Since Galvanometer is a very sensitive instrument therefore it can’t measure heavy currents. In order to     convert a Galvanometer into an Ammeter, a very low resistance known as "shunt" resistance is     connected in parallel to Galvanometer. Value of shunt is so adjusted that most of the current passes     through the shunt. In this way a Galvanometer is converted into Ammeter and can measure heavy     currents without fully deflected.










VALUE OF SHUNT RESISTANCE

 
















Let resistance of galvanometer = Rg and it gives full-scale deflection when current Ig is passed through     it. Then,

Vg = IgRg -------(i)

    Let a shunt of resistance (Rs) is connected in parallel to galvanometer. If total current through the     circuit is I.



























Then current through shunt:

Is = (I-Ig)

    potential difference across the shunt:

Vs= IsRs


or 
              Vs = (I – Ig)Rs -------(ii)

    But

V=Vg
(I - Ig)Rs = IgR



CONVERSION OF GALVANOMETER INTO VOLTMETER


Since Galvanometer is a very sensitive instrument, therefore it can not measure high potential     difference. In order to convert a Galvanometer into voltmeter, a very high resistance known as "series     resistance" is connected in series with the galvanometer.


VALUE OF SERIES RESISTANCE























 Let resistance of galvanometer = Rg and resistance R(high) is connected in series to it. Then     combined resistance = (R+ Rx).


    If potential between the points to be measured = V and if galvanometer gives full-scale deflection,     when current "Ig" passes through it. Then,
 

V = Ig (Rg + Rx
V = IgR+ IgRx 
V – IgR= IgRx 
Rx = (V – IgRg)/Ig


    Thus Rx can be found.


3 years ago

Post Your Answer

More Questions On Electric Current

Ask Experts

Have any Question? Ask Experts
Post Question
 
Answer ‘n’ Earn
Attractive Gift
Vouchers
To Win!!!
Click Here for details
what is the difference between emf and potential difference?
 
 
see the difference between emf and potential difference emf =potential difference+ current* internal resistance if the internal resistance is zero then emf=potential difference.
  img
Sher Mohammad 3 months ago
Pl help in answering the question as attached.
 
 
Let’s say the current in 5 ohm branch is I. This current gets divided into 2 ohm resistor and 4 ohm resistor. Let current in 2 ohm branch be I 1 ,so current in 4 ohm branch will be I-I...
  img
Aziz Alam one month ago
simple but well defined strcture and working of the electric motor,it confuses me a lot
 
 
Have a look here howstuffworks.com/motor1.htm
 
Ashwin 2 months ago
A small block of mass 100 g moves with uniform speed in a horizontal circular groove, with vertical side walls, of radius 25 cm. If the block takes 2 s to complete one round, find the normal...
 
 
The speed of the block is The acceleration of the block is towards the centre. The only force in this direction is the normal contact force due to the side walls. Thus, from Newton’s...
  img
Apoorva Arora 3 months ago
Two point charges q and 4q are held at separation .At what distance the electric field due to them is zero?
 
 
q-----x---,---(d-x)------4q x^2/(d-x)^2=1/4 x/(d-x)=1/2 d/x-1=2 d/x=3/2 x=2/3d
 
vamsi 10 months ago
 
q-----x---,---(d-x)------4q x^2/(d-x)^2=1/4 x/(d-x)=1/2 d/x-1=2 d/x=3/2 x=2/3d
 
GOROJANAPU KIRAN one year ago
Centre of mass. [ALTS-6 Q11]
 
 
Hi, the particles would lie on a circle, so COM would be <= R from origin...
  img
Shobhit Varshney 22 days ago
 
Yeah, only if they are kept in exactly opposite directionswith origin at the mid...
  img
Shobhit Varshney 22 days ago
 
Ok,Had the particles of equal mass be kept at equal distance from the origin,then COM would have lied at the origin...Right??
 
ANMOL SETH 22 days ago
View all Questions »