CBSE Class 12 · 2014 · Delhi · Geometrical OpticsVery Short Answer

WhatsApp Email
A biconcave lens made of a transparent material of refractive index is immersed in water of refractive index . Will the lens behave as a converging or a diverging lens? Give reason.

Answer: It behaves as a converging lens.

Solution

Here the surrounding medium is \emph{denser} than the lens material (), so . This reverses the sign of : a biconcave (normally diverging) lens therefore acts as a \emph{converging} lens in water.

CBSE Class 12 Board · 2014 · Delhi · Subjective

More board questions on Geometrical Optics

  1. The focal lengths of the objective and the eyepiece of a compound microscope are and respectively. If the tube length of the microscope is , the magnification obtained by the microscope for most suitable viewing by a relaxed eye …
    CBSE 2024View solution →
  2. The radius of curvature of a convex mirror is . It forms an image of an object which is half the size of the object. Find the separation between the object and the image.
    CBSE 2024View solution →
  3. \textbf{Case study (prism and total internal reflection):} A ray of light suffers successive refractions on passing through the two faces of a prism; . If the angle of incidence on the second surface exceeds th …
    CBSE 2024View solution →
  4. When a ray of light of wavelength and frequency is refracted into a denser medium:
    CBSE 2024View solution →
  5. The critical angle for a ray of light passing from glass to water is minimum for:
    CBSE 2024View solution →
  6. Three beams of red, yellow and violet colours are passed through a prism, one by one, under the same condition. When the prism is in the position of minimum deviation, the angles of refraction from the second surface are and respectively. Then:
    CBSE 2024View solution →