AQA GCSE Lenses (Physics)
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Lenses
A lens forms an image by refracting (bending) light rays.
There are two types of lenses
1.Convex (converging lens)
2.Concave (diverging lens)
Convex (converging lens)
A convex lens will bring parallel rays of light to a focus at a point called the principal focus.
The distance between the centre of the lens and the principal focus is known as the focal length.
Concave (diverging lens)
In a concave or diverging lens, the light rays will spread out.
The principal focus is where the rays of light would appear to diverge from.
The focal length is the distance from the principal focus to the centre of the lens.
Symbols for lenses.
In physics we use symbols to represent the two types of lenses.
Practice Question
1.State the role of a lens
2. Describe the difference in appearance of a convex and concave lens.
3. Define the term focal length
4. Describe what happens to light rays when they pass through a convex lens
5. Describe what happens to light rays when they pass through a concave lens.
Absorption and Emission of EM Radiation
JJ Thomson and Plum pudding model
Ernest Rutherford and the Nuclear Model
Niels Bohr changing the Nuclear Model
Discovering the Proton and Neutron
Measuring radiation from radioactivity
Radiation types and properties
Random nature of radioactive decay
Radioactive contamination or irradiation
Hazards of contamination and irradiation
Studies on the effects of radiation on humans
Different half lives of radioactive isotopes
Nuclear Fission Chain Reaction
Writing nuclear fission equations
Drawing ray diagrams for a concave lens
Drawing Ray Diagram to produce a virtual image for a convex lens
Drawing ray diagram to produce a real image for a convex lens.
Specular and Diffuse Reflection
Seeing Coloured Objects Part 2
Viewing objects through coloured filters
Transparent, Translucent and Opaque