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AP® Physics 1 & 2

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Moderate

Current in Ammeter: Resistor and Capacitor Circuit

APPH12-1W4XKZ

Created for Albert.io. Copyright 2016. All rights reserved.

The circuit shown includes an $80\text{ V}$ battery connected to four $100\text{ ohm}$ resistors, labeled ${ R }_{ 1 }$, ${ R }_{ 2 }$, ${ R }_{ 3 }$ and ${ R }_{ 4 }$. Resistor $R_{ 4 }$ is connected in parallel with a capacitor. An ammeter, $A$, is installed to measure the current flowing into the capacitor.

A short time after closing the switch the instantaneous current in $R_{ 3 }$ is $62\text{ milliamps}$ and the instantaneous current in $R_{ 4 }$ is $25\text{ milliamps}$.

At this same instant, what is the current measured by the ammeter?

A

$800\text{ milliamps}$

B

$200\text{ milliamps}$

C

$87\text{ milliamps}$

D

$37\text{ milliamps}$