Title: Electricity, Magnetism and Light Principles
Introduction: Modern devices such as cell phones and methods of generating electricity operate
based on specific physics principles. Michael Faraday’s principle of electromagnetic induction is
considered a great discovery for the modern world
Thesis statement: From the operation of cell phone chargers to the operation of LED lights, the
physics principles of electromagnetic induction and electroluminescence depict how electricity,
magnetism, and light are connected.
Main idea: From the case scenario Mandy’s cell phone was not charged, and when she found a
charging station with a USB port she plugged it in.
In most regions, electricity for domestic use ranges from 220 volts to 240 volts.
Charging stations generate a 5 volts electricity allowing cell phones to be charged efficiently
Step-down in voltage is made possible by a step-down transformer enables the much higher AC
voltage and current to be lowered to a safer voltage level to be used by small devices.
Main idea: After plugging her cell phone, Mandy knew that it was charging because of the LED
indicator light on the screen.
The LED indicator light works based on the law of electroluminescence
The principle is founded on both electrical and optical phenomenon when a material emits lights
when exposed to a strong electrical field
The functionality behind the electroluminescence principle in LED lights ...