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1. Chapter – 10 “Light”
3 marks type
1. A 4.5 cm needle isplaced12cm away froma convex mirrorof focal length15 cm.Give the
locationof image andmagnification.Describe whathappenstothe image asthe needle is
movedfartherfromthe mirror.
2. (a) State Snell’slawof refraction.
(b) Whena ray of lighttravellinginairentersobliquelyintoaglassslab,itisobservedthatthe light
ray emergesparalleltothe incidentraybutit isshiftedsidewaysslightly.Draw aray diagram to
illustrate it.
3. A studentwantsto projectthe image of a candle flame ona screen60 cm in frontof a mirrorby
keepingthe flame atadistance of 15 cm fromitspole.
a. Write the type of mirrorhe shoulduse.
b. Findthe linearmagnificationof the image produced.
c. What is the distance betweenthe objectanditsimage?
d. Draw a ray diagramto showthe image formationinthiscase.
4. An objectof height5 cm is placedperpendiculartothe principal axisof aconcave lensof focal
length10 cm. If the distance of the objectfromthe optical centre of the lensis20 cm, determine
the position,nature andsize of the image formedusingthe lensformula.
5. The nature,size andpositionof image of anobjectproducedbya lensormirror are as shown
below.Identifythe lens/mirror(X) usedineachcase and draw the correspondingcompleteray
diagram,(size of the objectabouthalf of the image).
5 marks type
6. An objectof height4.0 cm isplacedat a distance of 30 cm fromthe optical centre ‘O’of a convex
lensof focal length20 cm.Draw a ray diagramto findthe positionandsize of the image formed.
Mark optical centre ‘O’andprincipal focus‘F’on the diagram.Alsofindthe approximateratioof size
of the image tothe size of the object. [CBSE2018]
7. (a) Define principal focusof aspherical mirror.
(b) For whatpositionof the objectdoesa concave mirrorform a real,invertedanddiminishedimage
of the object?Drawthe ray diagram.
(c) An object4 cm highisplacedat a distance of 6 cm in frontof a concave mirrorof focal length12
cm. Findthe positionof the image formed.
8. (a) Write one use of concave mirroras well asconvex mirror.
(b) Draw ray diagramsfor the followingcaseswhenaray of light:
(i) passingthroughcentre of curvature of a concave mirror isincidentonit.
(ii) parallel toprincipal axisisincidentonconvex minor.
(iii) isincidentatthe pole of a convex mirror.
(iv) passingthroughfocusof a concave mirrorincidentonit.

2. 9. (a) A converginglensformsa real andinvertedimage of anobjectat a distance of 100 cm fromit.
Where shouldanobjectbe placedinfrontof the lens,sothat the size of the image istwice the size
of the object?Also,calculate the powerof alens.
(b) State lawsof refraction.
10. State the relationbetweenobjectdistance,image distance andfocal lengthof aconcave or
convex mirror.A concave mirror producestwotimesmagnifiedreal image of anobjectat10 cm
fromit. Findthe positionof the image.