Which of the following statements pertains to resistors only?

Question

Examoogle · Accepted Answer

They can dissipate desirable amount of power

Explanation: Resistors are passive electrical components that strictly dissipate electrical energy as heat, governed by Joule's law. Unlike capacitors or inductors, they cannot store energy in electric or magnetic fields, and they do not exhibit dynamic reactance behavior.

Working Principle: The principle of resistance is based on the collisions between charge carriers (electrons) and the lattice structure of the resistive material. This process converts kinetic energy into thermal energy ($P = I^2R$). Because they lack a mechanism for charge separation or field generation, they respond instantaneously to changes in voltage without inertial (inductive) or capacitive effects.

Key Formulas: $P = I^2 R$ — Power dissipated as heat; $P = \frac{V^2}{R}$ — Power dissipated in terms of voltage and resistance

Key Points: Resistors are purely dissipative, non-inductive, and non-capacitive components.; Energy dissipated by a resistor is irreversible and is converted into heat.; Inductors oppose changes in current ($L \frac{di}{dt}$), and capacitors oppose changes in voltage ($C \frac{dv}{dt}$), which resistors do not.

Advantages: Simple linear relationship between voltage and current (Ohm's Law).; Essential for current limiting and signal attenuation.

Disadvantages: Irreversible energy loss as heat.; Power handling limits based on physical size and thermal dissipation capacity.

Applications: Current limiting in LED circuits; Voltage division in signal processing; Load resistors for impedance matching

Additional Info: Option A is incorrect because capacitors oppose sudden changes in voltage, while inductors oppose sudden changes in current.. Option B is incorrect because resistors do not have the physical property (electric or magnetic field storage) required to store energy.. Resistors follow Ohm's law, $V = IR$, for linear resistors.

Answer: C is correct — Resistors function as dissipative elements that convert electrical energy into thermal energy based on the current and voltage applied, unlike reactive components.

Exam Tip: Always remember the 'V-I' behavior: Capacitors oppose V-change (V stays same), Inductors oppose I-change (I stays same), and Resistors provide instantaneous V-I tracking.

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