The Ammeter Your Physics Instructor Uses for In-Class Demonstrations Has $\varOmega$

Multiple Choice

The ammeter your physics instructor uses for in-class demonstrations has a resistance R_g and requires a current of 1.0 mA for full-scale deflection.The same ammeter can be used to measure currents of much greater values by wiring a shunt resistor of relatively small resistance,R_p ,in parallel with the ammeter.The shunt resistance needed to produce a full-scale current of 12 A is 3.5 m $\varOmega$ .What is the resistance of the ammeter,R_g?

A) 75 $\varOmega$ .
B) 35 $\varOmega$ .
C) 42 $\varOmega$ .
D) 28 $\varOmega$ .
E) 60 $\varOmega$ .