What are the disadvantages of resistors?
The electric current blocked by the resistor is wasted in the form of heat. Resistors are the passive components. Hence, they cannot control the flow of electrons or electric current through them. However, they can restrict the electric current to certain level.
Why are resistors considered loads?
In a circuit, an element which consumes electric power is considered as a load. Resistor also consumes power. So, resistor can be represented instead of load, or, every load is consuming power as the same way as resistor consumes. Example of load in electric circuits are appliances and lights.
Why can a shorted resistor be ignored in a short circuit?
Here we have a resistor with unlimited conductance, so all current flows through it. Therefore, the other resistor has no effective value. That’s why the 20 Ohm resistor can be ignored. In practical circuits, the short circuit resistance is not zero but small enough to consider it zero for practical use.
What happens when you decrease the resistance of a resistor?
Similarly, as we decrease the resistance of a variable resistor (open the valve) the voltage differential across the resistor decreases until, as we reach the end of the resistance (where we have essentially a short circuit) there is no appreciable voltage differential across the resistor.
Why do we call a resistor a passive element?
Passive element is one which does not generate, or modify nature of voltage or current. It dissipates energy or stores and releases energy. It needs an external energy source to operate. By this definition, resistor is a passive element, and so also are capacitor and inductor.
Why can a 20 ohm resistor be ignored?
When there is two resistor in parallel then the current divides itself accordance to conductance of the resistors. The more conductance the more current. Here we have a resistor with unlimited conductance, so all current flows through it. Therefore, the other resistor has no effective value. That’s why the 20 Ohm resistor can be ignored.