Analog and electronic circuits

Which correctly states Thevenin's theorem?

  1. AA linear circuit of sources and resistors, seen from two terminals, can be replaced by a single voltage source in series with a single resistor
  2. BThe current is the same everywhere in a circuit
  3. CRearranging all the resistors in parallel does not change the current
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Answer: A. A linear circuit of sources and resistors, seen from two terminals, can be replaced by a single voltage source in series with a single resistor

By Thevenin's theorem, a linear circuit of sources and resistors, seen from a pair of terminals, is equivalent to a voltage source equal to the open-circuit voltage in series with the resistance between the terminals when the sources are removed (the internal resistance). This makes it easy to find, for example, the current when the load changes. Replacing the circuit with a current source and a parallel resistor is Norton's theorem.

  • A. Correct. It can be replaced with a voltage source and series resistor.
  • B. The current is the same everywhere only in a series circuit.
  • C. Changing how resistors are connected generally changes the current.
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