question_answer

A galvanometer coil has a resistance of 15 \[\Omega \] and gives full scale deflection for a current of 4 mA. To convert it to an ammeter of range 0 to 6 A

A)  10 m\[\Omega \] resistance is to be connected in parallel to the galvanometer

B)  10 m\[\Omega \] resistance is to be connected in series with the galvanometer

C)  0.1 \[\Omega \] resistance is to be connected in parallel to the galvanometer

D)  0.1 \[\Omega \] resistance is to be connected in series with the galvanometer

Correct Answer: A

Solution :

                To convert a galvanometer into an ammeter, a shunt resistance in parallel is connected to galvanometer. Since, galvanometer G and shunt S are in parallel, hence \[{{i}_{g}}G=(i-{{i}_{g}})\]