Page 1 CBSE TEST PAPER-02 Class - XII Physics (Ray Optics) [ANSWERS] Ans1: The image is produced due to regular reflection of light but when we read a newspaper, because of diffused (irregular) reflection of light we are not able to see even a faint image. Ans2: 1 sin C µ = 1 1 1 sin 45 2 o µ = = Ans3: the two rays from the object PQ undergoes total internal reflection firstly at the face AB and then at BC forming the find image ' ' P Q (real and inverted image) Ans4: As we know ( ) 1 2 1 1 1 1 f R R µ ? ? = - - ? ? ? ? When R1 and R2 gets interchanged focal length of the lens remains the same hence position of the image will not change. Ans5: At the surface AB 1 1 i r d = - At the surface AC 2 2 1 2 e r Thus d d d d = - = + ( ) 1 2 (1) i e r r d = + - + - - - - 2 µ = Page 2 CBSE TEST PAPER-02 Class - XII Physics (Ray Optics) [ANSWERS] Ans1: The image is produced due to regular reflection of light but when we read a newspaper, because of diffused (irregular) reflection of light we are not able to see even a faint image. Ans2: 1 sin C µ = 1 1 1 sin 45 2 o µ = = Ans3: the two rays from the object PQ undergoes total internal reflection firstly at the face AB and then at BC forming the find image ' ' P Q (real and inverted image) Ans4: As we know ( ) 1 2 1 1 1 1 f R R µ ? ? = - - ? ? ? ? When R1 and R2 gets interchanged focal length of the lens remains the same hence position of the image will not change. Ans5: At the surface AB 1 1 i r d = - At the surface AC 2 2 1 2 e r Thus d d d d = - = + ( ) 1 2 (1) i e r r d = + - + - - - - 2 µ = In quadrilateral AQOR ( ) 360 90 o o A Q O R But Q R each ? + ? + ? + ? = ? = ? 180 (2) o A O Now in QOR ? ? + ? = - - - - ? 1 2 180 180 (3) o o Q O R or r r O ? + ? + ? = + + ? = - - - - - From (2) and (3) 1 (4) r r A + = - - - - - Substituting equation (4) in equation (1) d = i + e – A Or Ans6: Advantages (1) The image formed in reflecting type telescope is free from chromatic aberrations (2) The image formed is very bright due to its large light gathering power. NEWTONIAN TELESCOPE (REFLECTING TYPE) A + d = i + e Page 3 CBSE TEST PAPER-02 Class - XII Physics (Ray Optics) [ANSWERS] Ans1: The image is produced due to regular reflection of light but when we read a newspaper, because of diffused (irregular) reflection of light we are not able to see even a faint image. Ans2: 1 sin C µ = 1 1 1 sin 45 2 o µ = = Ans3: the two rays from the object PQ undergoes total internal reflection firstly at the face AB and then at BC forming the find image ' ' P Q (real and inverted image) Ans4: As we know ( ) 1 2 1 1 1 1 f R R µ ? ? = - - ? ? ? ? When R1 and R2 gets interchanged focal length of the lens remains the same hence position of the image will not change. Ans5: At the surface AB 1 1 i r d = - At the surface AC 2 2 1 2 e r Thus d d d d = - = + ( ) 1 2 (1) i e r r d = + - + - - - - 2 µ = In quadrilateral AQOR ( ) 360 90 o o A Q O R But Q R each ? + ? + ? + ? = ? = ? 180 (2) o A O Now in QOR ? ? + ? = - - - - ? 1 2 180 180 (3) o o Q O R or r r O ? + ? + ? = + + ? = - - - - - From (2) and (3) 1 (4) r r A + = - - - - - Substituting equation (4) in equation (1) d = i + e – A Or Ans6: Advantages (1) The image formed in reflecting type telescope is free from chromatic aberrations (2) The image formed is very bright due to its large light gathering power. NEWTONIAN TELESCOPE (REFLECTING TYPE) A + d = i + e Ans7: fo + fe = 101 --------- (1) 100 fo M fe = = fo = 100 fe ---------- (2) Substituting equation. (2) in equation (1) fe + 100fe = 101 101fe = 101 Substituting fe in equation (2) fo = 100 ×1 Ans8: (a) convex lens (b) 1 1 1 U f ? - = When U ? 8 1 1 f ? = i.e In the given graph f = 10cm. ' ' ' ' ' (1) ABC and A B C are similar A B B C AB BC ? ? = - - - - ' ' ' ' ' DCF and A B F are similar A B B F DC FC ? ? = ( ) ' ' ' ' ' (2) A B B F A B DC AB DC FC AB ? = = - - - - = ? fe = 1cm fo = 100cm f ? = Page 4 CBSE TEST PAPER-02 Class - XII Physics (Ray Optics) [ANSWERS] Ans1: The image is produced due to regular reflection of light but when we read a newspaper, because of diffused (irregular) reflection of light we are not able to see even a faint image. Ans2: 1 sin C µ = 1 1 1 sin 45 2 o µ = = Ans3: the two rays from the object PQ undergoes total internal reflection firstly at the face AB and then at BC forming the find image ' ' P Q (real and inverted image) Ans4: As we know ( ) 1 2 1 1 1 1 f R R µ ? ? = - - ? ? ? ? When R1 and R2 gets interchanged focal length of the lens remains the same hence position of the image will not change. Ans5: At the surface AB 1 1 i r d = - At the surface AC 2 2 1 2 e r Thus d d d d = - = + ( ) 1 2 (1) i e r r d = + - + - - - - 2 µ = In quadrilateral AQOR ( ) 360 90 o o A Q O R But Q R each ? + ? + ? + ? = ? = ? 180 (2) o A O Now in QOR ? ? + ? = - - - - ? 1 2 180 180 (3) o o Q O R or r r O ? + ? + ? = + + ? = - - - - - From (2) and (3) 1 (4) r r A + = - - - - - Substituting equation (4) in equation (1) d = i + e – A Or Ans6: Advantages (1) The image formed in reflecting type telescope is free from chromatic aberrations (2) The image formed is very bright due to its large light gathering power. NEWTONIAN TELESCOPE (REFLECTING TYPE) A + d = i + e Ans7: fo + fe = 101 --------- (1) 100 fo M fe = = fo = 100 fe ---------- (2) Substituting equation. (2) in equation (1) fe + 100fe = 101 101fe = 101 Substituting fe in equation (2) fo = 100 ×1 Ans8: (a) convex lens (b) 1 1 1 U f ? - = When U ? 8 1 1 f ? = i.e In the given graph f = 10cm. ' ' ' ' ' (1) ABC and A B C are similar A B B C AB BC ? ? = - - - - ' ' ' ' ' DCF and A B F are similar A B B F DC FC ? ? = ( ) ' ' ' ' ' (2) A B B F A B DC AB DC FC AB ? = = - - - - = ? fe = 1cm fo = 100cm f ? = Combining equation (1) & (2) ' ' B C B F BC BF = Using sign conventions ' ' ' ' B C BC U B F B C FC B F f FC f ? ? = + = - = = = + - = + f U f f U fU ? ? ? ? - ? = - = - + Divide by U? f 1 1 1 U f ? - = + Or Hence derived 1 1 1 f U ? = -Read More

Offer running on EduRev: __Apply code STAYHOME200__ to get INR 200 off on our premium plan EduRev Infinity!