Photo AI
Lenses are used in spectacles to treat some vision defects - Edexcel - GCSE Physics - Question 3 - 2015 - Paper 1
Question 3
Lenses are used in spectacles to treat some vision defects. The two main lens types are converging lenses and diverging lenses. (i) Diverging lenses always produce ... show full transcript
Worked Solution & Example Answer:Lenses are used in spectacles to treat some vision defects - Edexcel - GCSE Physics - Question 3 - 2015 - Paper 1
Step 1
Which row of the table describes the images produced by a converging lens?
Answer
For a converging lens, the image produced can be either real or virtual depending on the position of the object relative to the focal point. The size of the image can also be either magnified or diminished. Therefore, the correct option is B: either real or virtual; either magnified or diminished.
Step 2
Describe how the power of a lens is related to its shape.
Answer
The power of a lens, denoted by the symbol P, is defined as the reciprocal of its focal length (f) in meters:
P = rac{1}{f}
A lens with a shorter focal length produces a greater power, resulting in a stronger lens. Conversely, a lens with a longer focal length has a lower power.
This means that the shape of the lens—whether it is biconvex, biconcave, or plano-convex—affects how light is brought to a focus and thus its power. A biconvex lens has a positive power and converges light, while a biconcave lens has a negative power and diverges light.