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
VOLTAGE means?
 
 
Voltage, also called electromotive force, is a quantitative expression of the potential difference in charge between two points in an electrical field. The greater the voltage, the greater...
 
Indu 5 months ago
 
measure of current
 
akarsh 5 months ago
a potentiometer consist of a wire of lenght 4m and internal resistance 10ohm. if connected to a cell of emf 3v the potential gradient across the wire
 
 
By internal resistance, we guess you mean the resistance of the wire. We will assume the cell has zero internal resistance. Then potential gradient across the wire is 3V/4m = 0.75 V/m.
  img
Sandeep Pathak 26 days ago
define the thevenins theorem?
 
 
Get a circuit containing one voltage source and one resistor.
 
srujanapriya 8 months ago
 
Get a circuit containing one voltage source and one resistor
 
mahesh jadi 8 months ago
how many no. of images formed when three mirrors are placed at theta 60
 
 
We have studies that in two mirror system the number of images =360/ q –1. But in a three mirror system, the sum of the angles of the mirrors has to be 180° and mostly we go in for a...
  img
Vasantha Kumari 3 months ago
Two charge q &-2q are placed at some distnace the locus point in the place of the charge,where the potential is be zero? A.-Circle B.-Ellipse 3.-parabola
 
 
Ans is A:Circle let charge q is at (0,0)and -2q at(r,0) any point is (h,k) potential is zero so kQq/sqrt(h^2+k^2)=2kQq/sqrt((h-r)^2+k^2) => 4(h^2+k^2)=((h-r)^2+k^2)...
  img
Sher Mohammad 4 months ago
 
Answer is circle
 
Pinku 5 days ago
 
Circle
 
aswanth 4 months ago
The first overtone of an o0pen organ pipe beats with the first overtone of a closed organ pipe with a beat frequency of 2.2 Hz. The fundamental frequency of the closed organ pipe is 110 Hz....
 
 
Hello Student, Please find the answer to your question First overtone frequency ℓ 0 = ℷ ⇒ (v 1 ) 0 = v/ℷ’ = v/ ℓ 0 = 330/ ℓ 0 Fundamental frequency ℓ c = ℷ 1 /4 ⇒ ℷ 1 = 4 ℓ c...
  img
Aditi Chauhan 3 months ago
View all Questions »