The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
A galvanometer is a very sensitive device, it gives a full-scale deflection for the current of the order of microampere. Also for measuring current, the galvanometer has to be connected in series, and as it has a large resistance, this will change the value of the current in the circuit. To overcome these difficulties one attaches a small resistance called shunt resistance in parallel with the galvanometer coi