Advertisement Remove all ads

A Galvanometer of Resistance G is Converted into a Voltmeter to Measure Upto V Volts by Connecting a Resistance R1 in Series with the Coil. - Physics

Advertisement Remove all ads
Advertisement Remove all ads
Advertisement Remove all ads
Answer in Brief

A galvanometer of resistance G is converted into a voltmeter to measure upto V volts by connecting a resistance R1 in series with the coil. If a resistance R2 is connected in series with it, then it can measures upto V/2 volts. Find the resistance, in terms of R1 and R2, required to be connected to convert it into a voltmeter that can read upto 2 V. Also find the resistance G of the galvanometer in terms of R1 and R2

Advertisement Remove all ads

Solution

A high resistance that is connected in series with the galvanometer to convert it into voltmeter. The value of the resistance is given by `R=V/I_g-G`

Here,
V = Potential difference across the terminals of the voltmeter

Ig = Current through the galvanometer

G = Resistance of the galvanometer

When resistance R1 is connected in series with the galvanometer,

`R_1=V/I_g-G`

When resistance R2 is connected in series with the galvanometer,

 `R_2=V/(2I_g)-G" .....(ii)"`

From (i) and (i), we get

`V/(2I_g)=R_1-R_2 " and "G=R_1-2R_2`

The resistance R3 required to convert the given galvanometer into voltmeter of range 0 to 2V is given by

`R_3=(2V)/I_g-G`

R3=4(R1R2)(2R1R2)=3R12R2

G in terms of R1 and R2 is given by

G=R12R2

Concept: Moving Coil Galvanometer
  Is there an error in this question or solution?

Video TutorialsVIEW ALL [2]

Advertisement Remove all ads
Share
Notifications

View all notifications


      Forgot password?
View in app×