The resistance of an ideal ammeter is

Explanation: Ammeter • An Ammeter is a device which is connected in series of the circuit to find the current. • Ampere is the unit of current. • Ammeter is connected in series. So, if it is having a high resistance, it will affect the reading as the current will be reduced in the circuit. • So, an ammeter should have very small (ideally zero) resistance so that perfect reading can be obtained. ​ Important Points • For the voltmeter, the resistance should be infinite. • If resistance is low, it will provide an easy path for current and overall current will increase. This will affect the readings. Additional Information Converting Galvanometer to Ammeter • A galvanometercan be converted into an ammeterby connecting a shunt resistance in parallel to it. • The shunt resistance should have very low resistance.So, the ammeter (the parallel combination of galvanometer and shunt resistance) will have low resistance. • To convert a galvanometer into an ammeter of current rating ‘I’, a small resistance ‘S’ (shunt resistance) is connected in parallel across the galvanometer. Converting Galvanometer to Voltmeter • A galvanometer may be converted into a voltmeter by connecting a large resistance R in series with the galvanometer.

Ammeter: Ammeter is an instrument that is used to measure the current flowing through the circuit It has low resistance, ideally zero but practically it has a very low internal resistance The connecting ammeter in series allows all of the circuit current to pass through it and hence measure it Voltmeter: A voltmeter is an instrument that is used to measure the voltage across two terminals in a circuit Voltmeter ideally has infinite resistancezero but practically it has a very highinternal resistance Connecting the voltmeter with infinite resistance in parallel ensures no current flows through the voltmeter and the voltage drop (IR) remains the same.