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Magnifying Glass Tilted Right

Theme D - Fields

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Rocket

Theme A - Space, Time & Motion

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Thermometer

Theme B - The Particulate Nature Of Matter

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Water Wave

Theme C - Wave Behaviour 

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Microscope

Theme E - Nuclear & Quantum Physics

🌟 Fun fact: It&#39;s like when you try to sprint, but the wind pushes against you. That&#39;s what self-induction does to electric currents!

<ul>
	<li>Definition: When a changing current in a conductor (like a coil or wire) creates a change in its own magnetic flux, we call this self-induction.</li>
	<li>Think of it: Like trying to move forward in a crowd, but everyone keeps pushing you back!</li>
</ul>

Example: Imagine turning up the volume on your headphones. As the volume (current) increases, the headphones try to resist that increase, thanks to self-induction.

<ul>
	<li>Lenz&#39;s law says that an induced emf will always resist the change causing it.</li>
	<li>So, when the current in the coil
	<ul>
		<li>Increases 📈: Induced emf tries to reduce it.</li>
		<li>Decreases 📉: Induced emf tries to increase it.</li>
		<li>Is constant 📏: No induced emf.</li>
	</ul>
	</li>
	<li>Example: It&#39;s like trying to push a swing. If you push it away (increase current), it comes back at you (induced emf reduces it). If you pull it towards you (decrease current), it pushes away (induced emf increases it).</li>
</ul>

<ul>
	<li>Set up: A coil + resistor in series connected to a signal generator. Measurements made using an oscilloscope.</li>
	<li>To calculate the &quot;effective resistance&quot; (technically called reactance)
	<ul>
		<li>\(Ip = \frac {VR}{1000}\)</li>
		<li>\(R = \frac {1000× VC}{VR}\)</li>
	</ul>
	</li>
	<li>Reactance increases with frequency due to self-inductance.</li>
</ul>

<ul>
	<li>Transformers adjust alternating voltage levels.</li>
	<li>Components
	<ul>
		<li>Input (Primary) coil.</li>
		<li>Output (Secondary) coil.</li>
		<li>Iron core for both coils.</li>
	</ul>
	</li>
	<li>How it works
	<ul>
		<li>Alternating current enters the primary coil.</li>
		<li>This creates a magnetic field around an iron core, which changes direction with the alternating current.</li>
		<li>The changing flux induces emf in the secondary coil. Voila! Energy transferred!</li>
	</ul>
	</li>
	<li>Cool Equations
	<ul>
		<li>Vs=&minus;Ns&times;&Delta;t&Delta;&Phi;​</li>
		<li>VsVp​=NsNp​
		<ul>
			<li>Step-Up Transformer: Ns&gt;Np so Vs&gt;Vp</li>
			<li>Step-Down Transformer: Ns&lt;Np so Vs&lt;Vp</li>
		</ul>
		</li>
	</ul>
	</li>
	<li>Example: Ever used a phone charger? That&#39;s a small transformer changing high voltage from the outlet to a safe level for your phone!</li>
</ul>

<ul>
	<li>High-Voltage Direct Current Transmission (HVDC)
	<ul>
		<li>Transmits power at very high voltages, reducing energy loss.</li>
		<li>Example: The Baltic Cable running between Germany and Sweden operates at 450kV. The energy loss is much less than transmitting at 230V.</li>
	</ul>
	</li>
	<li>International Collaboration
	<ul>
		<li>Different countries, different power frequencies. Challenges when connecting grids.</li>
		<li>Solutions: Undersea cables and HVDC links.</li>
		<li>Real-world tie-in: Countries helping each other! Like Netherlands sending power to the UK or the HVDC link between Italy and Greece.</li>
	</ul>
	</li>
</ul>

Important Takeaways: 🌍 Transformers aren&#39;t just in movies; they play a massive role in our daily lives. 🔌 Our world is so interconnected that countries often share power. 🧲 Self-induction can seem like nature&#39;s resistance, but with the right tools, it&#39;s super manageable!

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Happy Studying! 🚀📚

Theme D - Fields

Unlocking Self-Induction: Understanding Coils, Flux, and Transformers

Table of content

Self-Induction - The Basics

Lenz's Law and Self-Induction

Unlock the Full Content!

Theme D - Fields

Unlocking Self-Induction: Understanding Coils, Flux, and Transformers

Table of content

Self-Induction - The Basics

Lenz's Law and Self-Induction

Unlock the Full Content!