Results

• Explore basic electricity relationships.
• Explain basic electricity relationships in series and parallel circuits.
• Use an ammeter and voltmeter to take readings in circuits.
• Provide reasoning to explain the measurements and relationships in circuits.
• Build circuits from schematic drawings.
• Determine if common objects are conductors or insulators.

When electromagnetic radiation is absorbed by a material the energy it carries has to go somewhere. When lower energy waves, like radio and infrared waves, are absorbed there can be an increase in temperature of the absorbing material. Higher energy waves, like x-ray and gamma waves, can actually permanently damage or change materials. Learn about the different types of electromagnetic waves and how their energies can influence their effects on objects.

You have learnt about static electricity where charged particles (electrons) can move from one object into another giving objects an overall charge. In this unit1 you will learn about current electricity. This is when a continuous flow of charge can be created using a circuit made of conducting wires and an energy source.

The flicker of numbers on a handheld calculator, nerve impulses carrying signals of vision to the brain, an ultrasound device sending a signal to a computer screen, the brain sending a message for a baby to twitch its toes, an electric train pulling into a station, a hydroelectric plant sending energy to metropolitan and rural users—these and many other examples of electricity involve electric current, which is the movement of charge. Humanity has harnessed electricity, the basis of this technology, to improve our quality of life. 

There are many different processes and phenomena that emit electromagnetic radiation. Humans have taken advantage of many of these processes to develop technologies that use electromagnetic radiation.

The beauty of a coral reef, the warm radiance of sunshine, the sting of sunburn, the X-ray revealing a broken bone, even microwave popcorn—all are brought to us by electromagnetic waves. The list of the various types of electromagnetic waves, ranging from radio transmission waves to nuclear gamma-ray (γ-ray) emissions, is interesting in itself.

Even more intriguing is that all of these different phenomena are manifestations of the same thing—electromagnetic waves (see Figure 15.1). What are electromagnetic waves? How are they created, and how do they travel? How can we understand their widely varying properties? What is the relationship between electric and magnetic effects? These and other questions will be explored.

Photoelectric materials emit electrons when they absorb light of a high-enough frequency.

An explanation of wave interference and solution of a few examples to find the value of the total wave when two wave pulses overlap

The wavelength and frequency of a wave are related to one another by the speed of travel of the wave, which depends on the type of wave and the medium through which it is passing.

• Make waves with water, sound, and light and see how they are related.
• Discuss wave properties using common vocabulary.
• Explain how changing the frequency and amplitude affects the characteristics of the wave.
• Design an experiment to measure the speed of the wave.