This thinner-centred lens spreads parallel rays of light in air.

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ScienceOne small aha

Your new ahaConcave lens

A concave lens spreads a parallel beam outward. Source: Concave lens ↗

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46This wave behaviour produces spreading around obstacles or through openings.RECALL
Diffraction
It is strongest when the gap is comparable to the wavelength
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47SI unit of electric currentRECALL
ampere (A)
One of seven SI base units
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48SI unit of resistanceRECALL
ohm (Ω)
Named after Georg Ohm
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