[amp_mcq option1=”5 Ohm” option2=”50 Ohm or more” option3=”100 Ohm” option4=”6 Ohm E. None of the above” correct=”option2″]
The correct answer is: B. 50 Ohm or more
A voltage source is said to be stiff if the voltage across its terminals remains relatively constant when a load is connected to it. The internal resistance of a voltage source is the resistance of the source itself, and it is in series with the load resistance. The voltage drop across the internal resistance of the source causes the output voltage to decrease when a load is connected.
The voltage source will appear stiff when the load resistance is much greater than the internal resistance. This is because the voltage drop across the internal resistance will be small compared to the output voltage, and the output voltage will therefore remain relatively constant.
For a voltage source with an ideal voltage of 12V and an internal resistance of 0.5W, the voltage source will appear stiff when the load resistance is 50 Ohm or more. This is because the voltage drop across the internal resistance is 0.5V when the load resistance is 50 Ohm, and this is only 5% of the output voltage.
The other options are incorrect because they do not meet the condition that the load resistance must be much greater than the internal resistance.