A circuit you’re building needs an ammeter that goes from 0 mA to a full-scale reading of 50.0 mA. Unfortunately, the only ammeter in the storeroom goes from 0 μA to a full-scale reading of only 500 μA. Fortunately, you can make this ammeter work by putting it in a measuring circuit, as shown. This lets a certain fraction of the current pass through
the meter; knowing this value, you can deduce the total current.
Assume that the ammeter is ideal.
a. What value of R must you use so that the meter will go to full scale when the current I is 50.0 mA?
Hint: When I = 50.0 mA, the ammeter should be reading its maximum value.
b. What is the equivalent resistance of your measuring circuit?
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