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PRACTICE / EMF and internal resistance

Find the hidden open-circuit intercept

A source reads 11 V at its terminals while delivering 0.50 A, and 8 V while delivering 2.0 A.

What emf is consistent with a constant internal resistance?

Organize the givens & assumptions
  • First reading: 0.50 A, 11 V
  • Second reading: 2.0 A, 8 V

Constant ideal emf and positive Ohmic internal resistance over the stated interval; settled DC currents and negligible lead resistance. This is an assigned source model, not battery test data.

  1. A12 V12\ \mathrm V
  2. B11 V11\ \mathrm V
  3. C9.5 V9.5\ \mathrm V
  4. D2 V2\ \mathrm V

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