CLASS 5 · LEARNING KNOWLEDGE
Light sources and light propagation – basic principles
How it works
Light sources are objects that emit light themselves, such as the Sun or an incandescent lamp. Light propagates in a straight line as long as it does not encounter obstacles. A distinction is made between natural and artificial light sources. Light can be reflected, refracted, or absorbed. The visibility of objects depends on whether light from them reaches the eye. Shadows are created when light is blocked by an opaque object.
Note
Light sources emit light that propagates in a straight line; only luminous objects are true light sources, while others become visible by reflecting light.
Light sources emit light that propagates in a straight line; only luminous objects are true light sources, while others become visible by reflecting light.
An example
Which of the following objects is a natural light source?
The Sun is a natural light source because it produces light itself. A mirror, the Moon, or a white sheet of paper only reflect light.
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50 Exercises
To the learning unit →Own explanation and own practice exercises by AmyMath. Subject reference framework: Physics. The topic assignment may vary by federal state.