Four ammeters with identical internal resistances $r$ and a resistor of resistance $R$ are connected to a current source as shown in figure. It is known that the reading of the ammeter $A_1$ is $I_1 = 3\ A$ and the reading of the ammeter $A_2$ is $I_2 = 5\ A$ . Determine the ratio of the resistances $R/r$ .
  • A$9$
  • B$3$
  • C$1/9$
  • D$1/3$
Diffcult
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