Self Assessment-Class 10 -Science- Physics-Chapter 10 – Light – Reflection and Refraction

Class 10 -Science-Self Assessment- Physics-Chapter 10 – Light – Reflection and Refraction

Very Short Answer:

Q1. A concave mirror is held in water. What would be the change in the focal length of the mirror? 

Q2.  What is the difference between the virtual images produced by (i) plane mirror,  (ii) concave mirror, (iii) convex mirror?  

Q3 Show that if a ray of light is reflected successively from two mirrors inclined at an angle , the deviation of the ray does not depend upon the angle of incidence. 

Q4. Use the mirror equation to deduce that an object placed between f and 2f of a concave mirror produces a real image beyond 2f. 

Q5. Show that a convex mirror always produces a virtual image independent of the location of the object. 

Short Answer

Q1. Why a concave mirror of small aperture forms a sharper image? 

Q2. What do you understand by the term ‘parallax’? 

Q3. How can you distinguish between three different mirrors just by looking at them?

Q4. What is the effect of size of mirror on the nature of image ? 

Q5. Is irregular reflection follows the laws of reflections or not ?

Long answer

Long answer

Q1. Find formulae for  magnification produced in the following cases : (i) concave mirror, when image formed is real (ii) concave mirror, when image formed is virtual (ii) convex mirror. 

Q2. Draw a ray diagram to show the formation of image of an object placed between the pole and centre of curvature of a concave mirror. Derive the formula connecting object distance (u), image distance (v) and focal length (f) for this particular case for the given concave mirror. State clearly the assumptions and sign conventions used. 

Q3. Express magnification produced by a spherical mirror in terms of

(i) u and f

(ii) v and f.

Numerical Problems

Q1. A 2.0 cm tall object is placed perpendicular to the principal axis of a convex lens of 1 focal length 10 cm. The distance of the object from the lens is 15 cm. Find the position, nature and size of the image forms.

Q2. (a) A concave mirror produces three times enlarged image of an object placed at 10 cm in front of it. Calculate the focal length of the mirror.

      (b) Show the formation of the image with the help of a ray diagram when object is placed 6 cm away from the pole of a convex mirror.

Q3. An object 1 cm tall is placed at a distance of 15 cm from a concave mirror of focal length 10 cm. Find the position, size and nature of the image formed.