What is the position of the image when an object is placed at a distance of 20cm from a concave mirror of focal length 20cm?
Download our app for free and get startedPlay store
Object distance, u = -20cm Focal length, f = -20cm (concave mirror) lmage distance, v = ?$\frac{1}{\text{v}}+ \frac{1}{\text{u}}=\frac{1}{\text{f}}$
$\Rightarrow\frac{1}{\text{v}}+ \frac{1}{(-20)}=\frac{1}{\text{(-20)}}$
$\Rightarrow \frac{1}{\text{v}}=0$
$\therefore \text{v}=\text{infinity}$
art

Download our app
and get started for free

Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*

Similar Questions

  • 1
    Draw ray diagrams showing the image formation by a concave lens when an object is placed:
    Beyond twice the focal length of the lens.
    View Solution
  • 2
    Light travels more quickly through water than through glass:
    1. Which is optically denser: Water or glass?
    2. If a ray of light passes from glass into water, which way will it bend: Towards the normal or away from the normal?
    View Solution
  • 3
    “A concave mirror of focal length ‘f’ can form a magnified erect as well as an inverted image of an object placed in front of it.” Justify this statement stating the position of the object with respect to the mirror in each case for obtaining these images.
    View Solution
  • 4
    Draw ray diagrams showing the image formation by a concave mirror when an object is placed:
    Between pole and focus of the mirror.
    View Solution
  • 5
    Explain with a suitable diagram, how a concave mirror converges a parallel beam of light rays. Mark clearly the pole, focus and centre of curvature of concave mirror in this diagram.
    View Solution
  • 6
    A 4 cm tall object is placed on the principal axis of a convex lens. The distance of the object from the optical centre of the lens is 12cm and its sharp image is formed at a distance of 24cm from it on a screen on the other side of the lens. If the object is now moved a little away from the lens, in which way (towards the lens or away from the lens) will he have to move the screen to get a sharp image of the object on it again? How will the magnification of the image be affected?
    View Solution
  • 7
    What type of lens is shown in the diagram on the right? What will happen to the parallel rays of light? Show by completing the ray diagram.
    View Solution
  • 8
    Name the type of mirrors used in the design of solar furnaces. Explain how high temperature is achieved by this device.
    View Solution
  • 9
    What is meant by:
    1. Principal focus of a convex mirror.
    2. Focal length of a convex mirror?
    View Solution
  • 10
    It is desired to obtain an erect image of an object, using concave mirror of focal length of 12cm.
    Where will the image of this object be, if it is placed 24cm in front of the mirror? Draw ray diagram for this situation also to justify your answer.
    Show the positions of pole, principal focus and the centre of curvature in the above ray diagrams.
    View Solution