Dioptre power of an concave lens of 10 cm focal length is_______________?

Related Mcqs:

1. A convex lens of focal length f1 and a concave lens of focal length f2 are placed in contact. The focal length of the combination is_____________?

   A. f2 + f1
   B. f2 – f1
   C. f1f2/f2+f1
   D. f1f2/f1-f2

2. Two convex lenses of equal focal length f are placed in contact the resultant focal length of the combination is______________?

   A. zero
   B. focus
   C. 2 f
   D. f/2

3. The power of a concave lens is_______________?

   A. real
   B. virtual
   C. positive
   D. negative

4. Power of a lens is one diopter if its focal length is

   A. 1 meter
   B. 2 meter
   C. ½ meter
   D. ¼ meter

   Submitted by: Rizwan Ayub Saadi

5. A convex lens acts as a diverging lens if the_________________?

   A. object is beyond C
   B. if the object is with in C
   C. if the object is within f
   D. both B and C

6. Unit of power of a lens is________________?

   A. meter
   B. watt
   C. diopter
   D. horsepower

7. A person wears spectates with concave lenses. It means that normally (when not using glasses), the image of distant objects is focused in his eyes:

   A. behind the retina
   B. in front of the retina
   C. on the retina
   D. on the blind spot

   Submitted by: Abid Hussain

8. A lens which converges a beam of parallel rays to a point is called______________?

   A. diverging (or concave) lens
   B. converging (or convex) lens
   C. plano concave lens
   D. plano convex lens

9. If a convex lens of large aperture fails to converge the light rays incident on it to a single point, it is said to suffer from______________?

   A. chromatic aberration
   B. spherical aberration
   C. both spherical and chromatic
   D. distortion

10. A point where the incident parallel rays of light converge or appear to diverge after passing through a lens is called______________?

    A. center of curvature
    B. focus
    C. optical center
    D. aperture