Inducing Current

Front

Magnetic Flux Noun

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[mag-net-ik fluhks]

Back

Magnetic Flux

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A measure of the total magnetic field passing through a given area, proportional to field strength and the perpendicular area.

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Example: Magnetic flux measures the number of magnetic field lines passing through a surface. Flux is maximum when the surface is perpendicular to the lines and minimum when parallel.

Front

Electromotive Force (EMF) Noun

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[uh-lek-troh-moh-tiv fors]

Back

Electromotive Force (EMF)

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The energy provided per unit of charge by an energy source, which acts as the 'electrical pressure' driving current.

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Example: Rotating a wire coil within a magnetic field induces an electromotive force (EMF), creating an electric current that powers the light bulb.

Front

Volt (V) Noun

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[vohlt]

Back

Volt (V)

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The standard unit of measurement for electromotive force and electric potential difference, representing energy per unit of charge.

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Example: This diagram uses a water analogy to show that voltage is like water pressure; the greater the height (voltage), the stronger the 'push' causing the water (electric charge) to flow.

Front

Induction Noun

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[in-duhk-shuhn]

Back

Induction

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The process of producing an electromotive force and current in a conductor by changing the magnetic flux passing through it.

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Example: Moving a magnet near a coil of wire creates a changing magnetic field, which induces an electric current in the wire, as shown by the galvanometer.

Front

Faraday's Law Noun

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[fair-uh-days law]

Back

Faraday's Law

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A fundamental law of physics predicting how a changing magnetic field will induce an electromotive force in an electric circuit.

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Example: Moving a magnet toward or away from a coil of wire changes the magnetic field, which induces an electric current, as shown by the voltmeter's needle.

Front

Lenz's Law Noun

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[len-ziz law]

Back

Lenz's Law

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A principle stating that the direction of an induced current is always such that it opposes the change in magnetic flux.

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Example: Moving a wire through a magnetic field (between the N and S poles) forces electrons to move along the wire, creating an induced electric current.

Front

Motional EMF Noun

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[moh-shuhn-uhl ee-em-ef]

Back

Motional EMF

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An electromotive force induced in a conductor moving through a magnetic field, or by a change in the circuit's area.

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Example: Moving a conducting rod through a magnetic field creates a voltage (EMF), which pushes electric charges to flow as a current through the circuit.

Front

Area Vector Noun

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[air-ee-uh vek-ter]

Back

Area Vector

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A vector used to represent a surface area, with a magnitude equal to the area and a direction perpendicular to it.

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Example: This diagram shows a flat surface (like a wire loop) and its area vector (S), which points straight out (perpendicular) from the surface.

Front

Alternating Current (AC) Noun

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[awl-ter-nay-ting kur-uhnt]

Back

Alternating Current (AC)

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An electric current that periodically reverses its direction and continuously changes its magnitude over time.

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Example: This animation shows a piston pushing water back and forth in a pipe. This is like Alternating Current (AC), where electricity flows one way, then reverses.

Front

Wireless Induction Noun

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[wyer-lis in-duhk-shuhn]

Back

Wireless Induction

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The process where a changing magnetic field from one coil induces a current in a separate, nearby coil without physical contact.

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Example: Moving a magnet near a coil of wire creates a changing magnetic field, which induces an electric current in the coil without a direct connection.