Question

What should you do to a galvanometer to increase its range and convert it to an ammeter?

• A. Change the dial markings on the galvanometer
• B. Decrease its overall resistance
• C. Increase its overall resistance
• D. Use better batteries on it

Answer 1

The correct option is B Decrease its overall resistance

If we somehow decrease the overall resistance of the device, more current would flow in, right? That’s what ohm’s law says.
Now how can we decrease the overall resistance?
You know that if we connect two resistors in parallel, their equivalent resistance will be lesser than both their individual resistances. So that means if I connect a very low resistance in parallel with the galvanometer, its overall resistance decreases. And indeed, this is exactly how we convert the galvanometer into an ammeter.