Question

A circuit consists of a 3 V source and a 3 Ω resistor. With an ideal ammeter of zero resistance inserted, the current in the circuit is:

Options

• 0.99 A

• 3.00 A

• 0.048 A

• 1.00 A

Answer 1

An ideal ammeter adds no resistance, so \[I = \frac{V}{R} = \frac{3}{3} = 1.00\ \text{A}\] This is the true current; the properly shunted ammeter reads 0.99 A (close to ideal), while the bare galvanometer reads only 0.048 A.