Isaac Physics Ammeter Sensitivity Question Help

An ammeter has resistance R A =20Ω and can give a maximum current reading of 100mA. To increase the current the ammeter can measure, it can be placed in parallel with a resistor, known as a shunt resistor, as shown in the figure below. What value of R is needed in order for the ammeter to be able to measure an I in up to 5.0A?
pls help. thx

Reply 1

mosaurlodon

if 100mA goes to ammeter, how much current goes to resistor? (total current is 5A)

they both have the same V, as they are parallel, so setting up V=IR for each of them, will let you solve for R.

(edited 1 year ago)

Reply 2

IntelligentGuy

Original post

by mosaurlodon

if 100mA goes to ammeter, how much current goes to resistor? (total current is 5A)
they both have the same V, as they are parallel, so setting up V=IR for each of them, will let you solve for R.