A certain ammeter has an internal resistance of 1 $\Omega$ and a range from 0 to 50 mA.To make its range from 0 to 5 A, use: A)a series resistance of 99 $\Omega$ B)an extremely large (say 10⁶ $\Omega$series resistance C)a resistance of 99 $\Omega$in parallel D)a resistance of 1/99 $\Omega$ in parallel E)a resistance of 1/1000 $\Omega$ in parallel

Question

Quizplus · Accepted Answer

To make the range of the ammeter from 0 to 5 A, we need to add an external resistor in parallel. The resistance of the external resistor should be equal to the internal resistance of the ammeter divided by the desired range of the ammeter.
External resistance = internal resistance / range
External resistance = 1 Ω / 5 A = 1/5 Ω = 0.2 Ω
Out of the given options, only option D has a resistance of 1/99 Ω which is closest to 0.2 Ω. Therefore, option D is the best choice.

A Certain Ammeter Has an Internal Resistance of 1 Ω\OmegaΩ And a Range from 0 to 50 MA

A Certain Ammeter Has an Internal Resistance of 1 $\Omega$ And a Range from 0 to 50 MA