A moving coil galvanometer has a resistance of 25W and gives a full scale deflaction for a current of 10 mA.
How will you convert it into a voltmeter having range 0-100 V?

Question

Q. A galvanometer has a resistance of 30

Ω

and a current of 2.0 mA gives full-scale deflection. How will you convert this galvanometer into a voltmeter of 0.2 volt range?

Answer 1

Given $G = 25, l g = 10 m A = 10 \times 10$ power by $3 A, v = 100 V$

To find resistance(Rs)

Formula $R^{'} s = \frac{V}{l g - G}$

Calculations by formula

$R^{'} s = \frac{100}{(10 \times 10^{- 3} - 25}$

$= 10000 - 25$

$= 9975$

Ans- resistance by $9975 Ω$

GivenG=25,lg=10mA=10×10 power by 3A,v=100VTo find resistance(Rs) Formula R′s=Vlg−GCalculations by formulaR′s=100(10×10−3−25=10000−25=9975Ans- resistance by 9975Ω