Question

An ideal ammeter (zero resistance) and an idel voltmeter (infinite resistance) are connect as shows in Fig. `6.47`. The ammeter and the voltmeter readings are

A. `6.25A, 3.75 V`
B. `3.00 A, 5V`
C. `3.00 A, 3.75 V`
D. `6.00 A, 6.25 V`

Answer 1

Correct Answer - B
Total resistance is
`((5 xx 15)/(5 xx 15) + 1.25)`
`= ((75)/(20) + 1.25) Omega = (3.75 + 1.25) Omega = 5 Omega`
`I = (20)/(5) A = 4 A`
Current through `5 Omega` is `(15)/(20) xx 4A = 3A`
Voltmeter reading = Potential drop across `1.25 Omega`
`= 4 xx 1.25 V = 5 V`