A galvanometer having a coil resistance of `60 Omega` shows full scale defection when a current of `1.0 A` passes thoguth it. It can vbe convered into an ammeter to read currents up to `5.0 A` by

Options

A. Putting in parallel a resistance of 15 `Omega`
B. Putting in parallel a resistance of 240 `Omega`
C. Putting in series a resistance of 15 `Omega `
D. Putting in series a resistance of 240 `Omega `

Answer

A

Explanation

`Ig=1.0A, G=60q, I=5.0A`
`S=(I_(g))/(I-I_(g))G`
`G=(1.0)/(5.0-1.0)=60`
`=15 Omega ` in parallel