12.1 CURRENT AND CHARGE To make an electric current pass around a circuit, it must be complete + include a source of potential difference, such as a battery. Current is the rate of the flow of charge in the wire or component. The current is due to the passage of charged particles: Charge carriers. In…

8.1 FORCE AND ACCELERATION: Motion without force: On an icy road, drivers are careful due to the tires of cars having little to no grip. Moving from a standstill on ice is a challenge. Stopping on ice is almost impossible. Any pushing force is opposed by friction in the opposite direction to motion, provided that…

5.1 REFRACTION OF LIGHT: Wave theory of light is used to explain the reflection and refraction of light. When the effect of lenses or mirrors on paths, we consider the drawing of diagrams using light rays and normals. Light rays represent the direction of travel of the waterfronts. And the normal is an imaginary line…

4.1 WAVES AND VIBRATIONS Types of waves: Waves that pass through a substance are vibrations which pass through that substance. Sound waves in air are created by making a surface vibrate so it sends compression waves through the surrounding air. Sound waves, seismic waves and waves on strings are known as mechanical waves.   Longitudinal…

3.1 THE PHOTOELECTRIC EFFECT: What is the photoelectric effect? If radiation of high enough frequency is shone onto the surface of a metal, it will emit electrons instantly. For most metals, the required frequency is in the ultraviolet region. Because of the way atoms are bonded together in metals, metals contain free electrons that are able to…

2.1 THE PARTICLE ZOO: Space invaders: Cosmic rays are high energy particles that travel through space from the stars, including the sun. Cosmic rays create short-lived particles and antiparticles. Most cosmic rays are fast moving protons or small nuclei. They collide with gas atoms creating showers of particles and antiparticles. By using cloud chambers and…

1.1 INSIDE THE ATOM:   Atoms are so small (10–10 ), need an electron microscope to view them. Through Rutherford’s alpha-scattering experiment, we know that every atom contains: A positively charged nucleus. Electrons surrounding the nucleus. Word nucleon is used for a proton or a neutron in the nucleus. Each electron has a negative charge. Because…

Types of wave Waves may be mechanical (i.e. they require a medium such as air or water to propagate) or electromagnetic (which propagate in a vacuum) Waves can be classified as: a) Transverse – here the disturbance is at right angles to the direction of the wave. Examples include water waves and light (electromagnetic). b)…