a mili ammeter whose resistance is 120 ohm has full scale deflection in the current of 5 mili A. how will you use it to measure Maximum current find the resistance of the mili ammeter ?value of Maximum current is 50 mili A
Solution,
Given,
Resistance of the ammeter, G = 120 ohm
Maximum current for full scale deflection, I = 5 mA
In order to show full deflection for 50 mA current, A shunt resistance must be connected in parallel so that 50 - 5 = 45 mA current passes through the shunt S.
Now since the ammeter and the shunt are connected in parallel, so the voltage developed across the ammeter and the shunt S will be same.
Thus,
Given,
Resistance of the ammeter, G = 120 ohm
Maximum current for full scale deflection, I = 5 mA
In order to show full deflection for 50 mA current, A shunt resistance must be connected in parallel so that 50 - 5 = 45 mA current passes through the shunt S.
Now since the ammeter and the shunt are connected in parallel, so the voltage developed across the ammeter and the shunt S will be same.
Thus,