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प्रश्न
What type of image is formed:
- in a plane mirror?
- on a cinema screen?
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उत्तर
- The image formed in a plane mirror is virtual because it forms even though the light rays do not actually meet.
- The image formed on a cinema screen is real because it is formed due to an actual meeting of the light rays.
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संबंधित प्रश्न
Explain the following term related to spherical lenses:- principal axis
Give one use each of a concave and a convex mirror.
Which type of mirror can form a real image?
Name the spherical mirror which has:
(a) virtual principal focus.
(b) real principal focus.
Name the two types of spherical mirrors. What type of mirror is represented by the:
front side of a shining steel spoon?
When a spherical mirror is held towards the sun and its sharp image is formed on a piece of a carbon paper for some time, a hole is burnt in the carbon paper.
Why is a hole burnt in the carbon paper?
A 50 cm tall object is at a very large distance from a diverging lens. A virtual, erect and diminished image of the object is formed at a distance of 20 cm in front of the lens. How much is the focal length of the lens?
- 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).
A concave lens produces an image 20 cm from the lens of an object placed 30 cm from the lens. The focal length of the lens is:
(a) 50 cm
(b) 40 cm
(c) 60 cm
(d) 30 cm
What do you understand by the focus and focal length of a spherical mirror? Show them on the separate diagrams for each of a concave mirror and a convex mirror.
Define the following terms in the context of spherical mirrors :
(i) Pole
(ii) Centre of curvature
(iii) Radius of curvature
(iv) Principal axis
Draw a ray diagram to show the formation of image by a concave mirror for an object placed between its pole and focus. State three characteristics of the image.
Define the following term in relation to concave mirror.
Radius of curvature
What is the relation between focal length and radius of curvature of a concave mirror?
Is real image always inverted?
Complete the following diagrams shown in the following figures by drawing the reflected rays.
Which of the following has curved reflecting surface?
How tall does a mirror have to be to fit an entire person’s body?
