You are working on a circuit that requires an ammeter with a full-scale reading of 75.0 mA. However, the only ammeter available in the storeroom has a range from 0 μA to a full-scale reading of 300.0 μA. The resistance of the ammeter is measured to be 60.0 Ω. To achieve the desired 75.0 mA reading capacity, you consider adding a resistor in parallel to the ammeter. Calculate the effective resistance of the modified ammeter (which is a combination of the ammeter and the parallel resistor).

• A. 0.240 Ω
• B. 0.138 Ω
• C. 0.236 Ω
• D. 0.158 Ω

Answer: (A)