Component of current in phase with the voltage is called component

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Component of current in phase with the voltage is called  component

Examoogle · Accepted Answer

Active

Explanation: In an AC circuit, the current can be resolved into two orthogonal components: one in phase with the supply voltage (active) and one lagging/leading by 90 degrees (reactive). The active component, also known as the wattful component, is responsible for the real power consumed by the load.

Working Principle: When a voltage $V$ is applied to a load with phase angle $\phi$, the total current $I$ is divided into $I_{active} = I \cos\phi$ and $I_{reactive} = I \sin\phi$. The active component $I \cos\phi$ performs useful work, such as generating heat or mechanical energy, while the reactive component merely oscillates energy back and forth between the source and the magnetic/electric fields of the load.

Key Formulas: $P = VI \cos\phi$ — Formula for Real (Active) Power in Watts; $I_{active} = I \cos\phi$ — The component of current in phase with voltage

Key Points: The active component is measured in Amperes and contributes to the power consumed.; The quadrature component ($I \sin\phi$) is also known as the wattless current.; In a purely resistive circuit, $\phi = 0$, so the entire current is active.; Power Factor ($PF$) is defined as the cosine of the angle between voltage and current, representing the ratio of active to apparent current.

Advantages: Maximizes energy efficiency in power systems.; Reduces transmission losses by minimizing reactive current flow.

Disadvantages: High reactive current increases the burden on transmission infrastructure without performing work.; Poor power factor results in higher electricity costs for industrial consumers.

Applications: Industrial motor drives; Transformer sizing and capacity management; Power factor correction capacitors

Additional Info: The term 'Active' signifies that this component does 'actual' work.. Option B (Quadrature) refers to the reactive component ($I \sin\phi$) which is 90 degrees out of phase.. Option D (Reactive) is the component that circulates energy and does not perform real work.

Answer: C is correct — The active component is the projection of the current vector onto the voltage vector, representing the part of the current that facilitates real power transfer.

Exam Tip: Always remember: 'Active' flows to the load to do work, while 'Reactive' just travels back and forth; think of it as a pendulum.

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