A galvanometer with a full-scale deflection of 20 mA is Converted to read 8 K by connecting a 395 \(\Omega\) resistor in series with it. Determine the internal resistance of the galvanometer

Folafoluwa2007

1 year ago

If you don't understand you can try this method

I=E/R+r
Where I=20mA=20/1000 , E=8 , R=395, r=?
20/1000=8/395+r
Cross multiply
8×1000=20(395+r)
8000=7900+20r
8000-7900=20r
100=20r
Then r=100/20= 5ohms

splenzye

2 years ago

the actual question is

A galvanometer with a full scale deflection of 20mA is converted to read 8 V by connecting a 395 ohms resistor in series with it. Determine the internal resistance of the galvanometer