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GATE 2025 EE – Question 19

Electric Circuits · Network Elements: Ideal voltage and current sources, dependent sources, R, L, C, M elements · 1 mark · Multiple choice

A nullator is defined as a circuit element where the voltage across the device and the current through the device are both zero. A series combination of a nullator and a resistor of value R, will behave as a

  1. resistor of value R.
  2. nullator.
  3. open circuit.
  4. short circuit.

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Show answer and explanation

Correct answer: (B) nullator.

Explanation

The nullator forces the current through the series branch to be zero, so the voltage across R is $R\cdot0=0$. The voltage across the nullator is also 0, so the total voltage across the combination is 0 with zero current: exactly the definition of a nullator.