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प्रश्न
Select the correct option:
A concave mirror is made by cutting a portion of a hollow glass sphere of radius 30 cm. The focal length of the concave mirror is:
पर्याय
24 cm
12 cm
15 cm
60 cm
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उत्तर
15 cm
Explanation:
Radius of curvature = R = 30 cm
Focal length of concave mirror f = `"R"/2`
f = `30/2 = 15` cm
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संबंधित प्रश्न
Define the following term in the context of spherical mirrors:- Pole
Image formed by a convex ______ is always virtual and smaller in size.
- A small object is placed 150 mm away from a diverging lens of focal length 100 mm.
- Copy the figure below and draw rays to show how an image is formed by the lens.
- Calculate the distance of the image from the lens by using the lens formula.
- Copy the figure below and draw rays to show how an image is formed by the lens.
- The diverging lens in part (a) is replaced by a converging lens also of focal length 100 mm. The object remains in the same position and an image is formed by the converging lens. Compare two properties of this image with those of the image formed by the diverging lens in part (a).
The diverging lens in part (a) is replaced by a converging lens also of focal length 100 mm. The object remains in the same position and an image is formed by the converging lens. Compare two properties of this image with those of the image formed by the diverging lens in part (a).
For what position of object, the image formed by a concave mirror is magnified and erect?
Write two more characteristics of the image.
What type of mirror can be used to obtain a real image of an object?
An object 5 cm high forms a virtual image of 1.25 cm high, when placed in front of a convex mirror at a distance of 24 cm. Calculate:
- the position of the image
- the focal length of the convex mirror.
What do you understand by the term real image?
Define the term Aperture.
