When a current of 5 mA is passed through a galvanometer having a coil of resistance 15 Ω, it shows full scale deflection. The value of the resistance to be put in series with the galvanometer to convert it into a voltmeter of range 0-10 V is :

Question

When a current of 5 mA is passed through a galvanometer having a coil of resistance 15 Ω, it shows full scale deflection. The value of the resistance to be put in series with the galvanometer to convert it into a voltmeter of range 0-10 V is : (A) 1.985 × 103 Ω (B) 2.045 × 103 Ω (C) 2.535 × 103 Ω (D) 4.005 × 103 Ω

Tardigrade Admin · Accepted Answer

ig = 5 × 10-3 A G = 15 Ω Let series resistance be R. V = ig (R + G) 10 = 5 × 10-3 (R + 15) R = 2000 - 15 = 1985 = 1.985 × 103 Ω

Q. When a current of $5 m A$ is passed through a galvanometer having a coil of resistance $15 Ω$ , it shows full scale deflection. The value of the resistance to be put in series with the galvanometer to convert it into a voltmeter of range $0 - 10 V$ is :

$1.985 \times 1 0^{3} Ω$

$2.045 \times 1 0^{3} Ω$

$2.535 \times 1 0^{3} Ω$

$4.005 \times 1 0^{3} Ω$

$i_{g} = 5 \times 1 0^{- 3} A$
$G = 15 Ω$
Let series resistance be R.
$V = i_{g} (R + G)$
$10 = 5 \times 1 0^{- 3} (R + 15)$
$R = 2000 - 15 = 1985 = 1.985 \times 1 0^{3} Ω$

Q. When a current of 5mA is passed through a galvanometer having a coil of resistance 15Ω, it shows full scale deflection. The value of the resistance to be put in series with the galvanometer to convert it into a voltmeter of range 0−10V is :

1.985×103Ω

2.045×103Ω

2.535×103Ω

4.005×103Ω