EASY
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What is the focal length of a convex lens positive or negative?
Important Questions on Refraction at Spherical Surface and Spherical Lens
EASY
Write the role of lenses in our daily life.
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Write the two differences between convex and concave lens.
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Which type of lens will you apply for reading small letters of a dictionary?
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A convex lens has a focal length of . At what distance should an object be placed in front of the lens to get a real image of the same size of the object?
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What is a lens? Name the two types of lens.
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What are the types of spherical lenses? Describe the principal focus, aperture and the optical centre of a spherical lens.
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Why is a convex lens called a convergent lens?
EASY
The central point of a lens is known as:
EASY
Define the focal length of spherical mirror.
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Define the principal focus of a convex lens.
MEDIUM
The following diagram shows the use of an optical device to perform an experiment of light.
As per the arrangement shown, the optical device is likely to be a _____.
EASY
If the lens is placed in water instead of air, how does its focal length change?
MEDIUM
What is meant by the optical centre of a convex lens?
MEDIUM
Write any three differences between a convex lens and a concave lens.
EASY
Which lens, thick or thin has greater focal length?
EASY
With the help of a ray diagram, explain the following terms: optical centre of a convex lens.
EASY
Name the piece of transparent materials which have one or two spherical surfaces.
EASY
Which lens is used for correcting the long-sightedness?
MEDIUM
Which type of lens is used in making telescopes-converging or diverging?
HARD
How will the following be affected on cutting lens into two equal halves along the principal axis?
(a) focal length
(b) intensity of image formed by half lens.
