Case 1 study:
As we all know the main purpose of a resistor in every circuit is to limit the current which is passing through on a certain load/component. And we also know that Voltage is directly Proportional to Current, as the voltage rise the current rise also and vice versa.
If we want to achieve a certain value of a current why don't we just lessen the voltage input and remove that resistor to save energy and the environment at the same time? Do you agree? State your thoughts regarding with this. And if your Disagree. State your thoughts also on why you disagree.
I don't agree. Extreme cases of voltage fluctuation can cause heavy damage to your life and property. There are 2 methods of reducing the value of current flowing in the circuit. That is increasing the resistance and decreasing the voltage.
For small rating applications, increasing resistance is suitable and for high rating applications decreasing voltage is suitable