Physics 9702 · AS & A Level · Resistance and resistivity

Resistance and resistivity — practice question

Three resistors, with resistances $R_1$, $R_2$ and $R_3$, are joined in series and have a total resistance of $500\,\Omega$. If they are then connected in parallel, the total resistance is found to be $50\,\Omega$. Which values match these results?

  • A$R_1 = 160\,\Omega,\; R_2 = 160\,\Omega,\; R_3 = 80\,\Omega$
  • B$R_1 = 200\,\Omega,\; R_2 = 200\,\Omega,\; R_3 = 100\,\Omega$
  • C$R_1 = 225\,\Omega,\; R_2 = 225\,\Omega,\; R_3 = 50\,\Omega$
  • D$R_1 = 230\,\Omega,\; R_2 = 230\,\Omega,\; R_3 = 40\,\Omega$

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