Question

A galvanometer gives full scale deflection with 0.006 A current. By connecting in to a `4990 Omega` resistance, it can be converted into a voltmeter of range 0-30V. If connected to a `(2n)/(249)Omega` resistance, it becomes an ammeter of range `0-1.5A`. The value of n is

Answer 1

`((I-I_g)/(I_g))S = V/(I_g) - R`
`(1.5 - 0.006)/(0.006) xx (2n)/(249) = 30/(0.006) - 4990`
`:. n~~5`.