A convex lens forms the image of the sun at a distance of 10 cm from t...
1) The image will form at the same distance which is at the focal length of the lens ie 10 cm. The use of lens having double aperture will help in better illumination of image.
2) The image will form at a distance of 5 cm. The focal length of the lens is inversely proportional to the power. So, when another lens of same aperture but double the power will be used, thr focal length will become half.
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A convex lens forms the image of the sun at a distance of 10 cm from t...
Effect of changing lens parameters on the distance of the image:
1) Same power but double the aperture:
- The power of a lens is determined by its curvature and refractive index, and it is given by the formula P = 1/f, where P is the power and f is the focal length of the lens.
- When the aperture of the lens is doubled, it means that the size of the lens has increased, but the power remains the same. This change in aperture does not affect the curvature or refractive index of the lens.
- As the power of the lens is determined by its curvature and refractive index, it is not affected by the change in aperture. Therefore, the focal length of the lens remains the same.
- The distance of the image formed by a convex lens is given by the lens formula: 1/u + 1/v = 1/f, where u is the object distance, v is the image distance, and f is the focal length of the lens.
- Since the power and focal length of the lens remain the same, the lens formula remains unchanged. Therefore, the distance of the image formed by the lens will also remain the same, which is 10 cm in this case.
2) Same aperture but double the power:
- When the power of the lens is doubled, it means that the curvature and refractive index of the lens have changed.
- The power of a lens is inversely proportional to its focal length. When the power is doubled, the focal length is halved.
- The lens formula remains the same, but the focal length changes. Therefore, the distance of the image formed by the lens will also change.
- In this case, since the power is doubled, the focal length will be halved. Let's assume the original focal length is f1 and the new focal length is f2 = f1/2.
- Using the lens formula, we can find the new distance of the image (v2) by substituting the new focal length (f2) and the original object distance (u) into the formula: 1/u + 1/v2 = 1/f2.
- By solving this equation, we can find the new distance of the image formed by the lens.
In summary, when the aperture of the lens is doubled while the power remains the same, the distance of the image formed by the lens remains unchanged. However, when the power of the lens is doubled while the aperture remains the same, the distance of the image will change and can be calculated using the lens formula.