Question

A galvanometer gives full scale deflection with `0.006 A` current. By connecting it to a `4990Omega` resistance, it can be converted into a voltmeter of range `0.30 V`. If connected to a `(2n)/249 Omega` resistance, it becomes an ammeter of range `0-1.5A`. the value of `n` is

Answer 1

`V = I_g (R + G)`
`0.30 = 0.006(4990 + G)`
`G = 10 Omega`

`I_g G = (I - I_g) S`
`0.006 xx 10 = (1.5 - 0.006) ((2n)/(249))`
`n = 5`.