A galvanometer has a resistance of `30Omega`. It gives full scale deflection with a current of 2mA. Calculate the value of resistance needed to convert it into an ammeter of range 0-0.3 A

Explanation

`q=3.2xx9^(-19)C, m=6.7xx10^(-27)kg, B=pi/2T`
`f=(qB)/(2pim)=(3.2xx10^(-19)(pi/2))/(2pixx(6.7xx10^(-27)))=(1.2xx10^7)`cycles/s