Question

A circuit you're building needs an ammeter that goes from 0 mA to a full-scale reading of 60.0 mA . Unfortunately, the only ammeter in the storeroom goes from 0μA to a full-scale reading of only 500μA. Fortunately, you've just finished a physics class, and you realize that you can make this ammeter work by putting a resistor in parallel with it, as shown in the figure (Figure 1) . You've measured that the resistance of the ammeter is 90.0 Ω , not the 0Ω of an ideal ammeter. so the questions are: What value of R must you use so that the meter will go to full scale when the current I is 60.0 mA ? and What is the effective resistance of your ammeter?

Answer 1