A galvanometer of resistance G is converted into a voltmeter of range 0-1 V by connecting a resistance R 1 in series with it. The additional resistance that should be connected in series with R 1 to increase the range of the voltmeter to -2 V will be :

Question

A galvanometer of resistance G is converted into a voltmeter of range 0-1 V by connecting a resistance R 1 in series with it. The additional resistance that should be connected in series with R 1 to increase the range of the voltmeter to -2 V will be : (A) R 1 (B) R 1+ G (C) R 1- G (D) G

Tardigrade Admin · Accepted Answer

<img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/physics/2d81bf128b9d2a94333365f186684df3-.png" /> ⇒ 2= i g ( R 1+ R 2+ G ) ldots(2) (1) % (2) ⇒ (1/2)=(G+R1/G+R1+R2) G + R 1+ R 2=2 G +2 h 1 (R2=G+R1)

Q. A galvanometer of resistance $G$ is converted into a voltmeter of range $0 - 1 V$ by connecting a resistance $R_{1}$ in series with it. The additional resistance that should be connected in series with $R_{1}$ to increase the range of the voltmeter to $- 2 V$ will be :

$R_{1}$

$R_{1} + G$

$R_{1} - G$

$G$

$\Rightarrow 2 = i_{g} (R_{1} + R_{2} + G) \dots (2)$
(1) $% (2)$
$\Rightarrow \frac{1}{2} = \frac{G + R _{1}}{G + R _{1} + R _{2}}$
$G + R_{1} + R_{2} = 2 G + 2 h_{1}$
$(R_{2} = G + R_{1})$

Q. A galvanometer of resistance G is converted into a voltmeter of range 0−1V by connecting a resistance R1​ in series with it. The additional resistance that should be connected in series with R1​ to increase the range of the voltmeter to −2V will be :

R1​

R1​+G

R1​−G

G

⇒2=ig​(R1​+R2​+G)…(2) (1) %(2) ⇒21​=G+R1​+R2​G+R1​​ G+R1​+R2​=2G+2h1​ (R2​=G+R1​)

Q. A galvanometer of resistance $G$ is converted into a voltmeter of range $0 - 1 V$ by connecting a resistance $R_{1}$ in series with it. The additional resistance that should be connected in series with $R_{1}$ to increase the range of the voltmeter to $- 2 V$ will be :

$R_{1}$

$R_{1} + G$

$R_{1} - G$

$G$

$\Rightarrow 2 = i_{g} (R_{1} + R_{2} + G) \dots (2)$
(1) $% (2)$
$\Rightarrow \frac{1}{2} = \frac{G + R _{1}}{G + R _{1} + R _{2}}$
$G + R_{1} + R_{2} = 2 G + 2 h_{1}$
$(R_{2} = G + R_{1})$