Question

An ammeter gives full scale deflection with a current of 1A.It is converted into an ammeter of range 10A.Find the ratio of the resistance of ammeter to the shunt resistance used.​

Answer 1

Answer:9:10

Explanation:

Answer 2

Answer:

So, the ratio of the resistance of ammeter to the shunt resistance used is 9:10.

Explanation:

We have given:

I = 10A

I_g = 1A

$S = \dfrac {I_g \times G}{I - I_g}$

Where,

S = Resistance of ampere

R = Resistance of slunt

G = Resistance of galvanometer

$S = \dfrac {1 \times G}{10 - 1}\\S = \dfrac G9\\G = 9S...(1)$

Now,

$R = \dfrac {G \times S}{S + G}$

From equation (1)

$R = \dfrac {9S \times S}{S + 9S}\\\\R = \dfrac {9S^2}{10S}\\\\R = \dfrac {9S}{10}\\\\\dfrac RS = \dfrac 9{10}$

So, the ratio of the resistance of ammeter to the shunt resistance used is 9:10.