Science
(a) Under what conditions can a convex lens form a virtual image?
(b) Why does a piece of paper catch fire if we allow sunlight to pass through a convex lens onto the paper?
Refraction Lens
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Answer
(a) A convex lens can form a virtual image when the object is placed between the lens and its focal point (F). In this case, the refracted rays diverge but their backward extensions appear to meet on the same side as the object, forming a virtual, erect, and magnified image.
(b) A piece of paper catches fire when sunlight is passed through a convex lens because the lens converges the parallel rays of sunlight to a single point called the focus. This concentration of light increases the energy density and temperature at that point. When the temperature rises above the ignition point of paper, it catches fire.
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Assertion (A): A point object is placed at a distance of 26 cm from a convex mirror of focal length 26 cm. The image will not form at infinity.
Reason (R): For above given system the equation gives v = ∞.
options
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