Selecting Ammeter Range for Mid-Scale Accuracy

Steps:

• Estimate the expected current in the circuit.
• Choose the range where the current is approximately half the full-scale deflection for best precision.
• Compare ranges: 1mA full scale suits <0.5mA; 10mA suits 1-5mA; 1A suits 0.1-0.5A; 10A suits 1-5A.
• For a current around 5mA, 0-10mA range places it near midpoint.

Why B is correct:

• Mid-scale readings (around 50% of full scale) minimize relative error in analog ammeters, per measurement accuracy principles.

Why the others are wrong:

• A: Too low range; 5mA would overload or peg the meter.
• C: Too high range; 5mA reads near zero, reducing precision.
• D: Excessively high; 5mA appears negligible, far from midpoint.

Final answer: B