DC Pandey Solutions (JEE Advance): Refraction of Light- 2 | DC Pandey Solutions for JEE Physics PDF Download

 Page 1


For JEE Advanced 
More than One Correct Options 
 
Q 1.  n number of identical equilateral prisms are kept in contact as shown in figure. If deviation 
through a single prism is ?. Then (n, m are integers) 
 
  (a) if n = 2m, deviation through n prisms is zero 
  (b) if n = 2m + 1, deviation through system of n prisms is ? 
  (c) if n = 2m, deviation through system of n prisms is ? 
  (d) if n = 2m + 1, deviation through system of n prisms is zero 
Q 2.  A ray of monochromatic light is incident on the plane surface of separation between two media x 
and y with angle of incidence i in the mediumx and angle of refraction r in the medium y. The 
graph shows the relation between sin i and sin r 
 
  (a) The speed of light in the medium y is 3 times than in medium x 
  (b) The speed of light in the medium y is 
1
3
times than in medium x 
  (c) The total internal reflection can take place when the incidence is in x 
  (d) The total internal reflection can take place when the incidence is in y 
Q 3.  Which of the following statements is/are true? 
  (a) In vacuum the speed of red colour is more than that of violet color 
(b) An object in front of a mirror is moved towards the pole of a spherical mirror from infinity, it 
is found that image also moves towards the pole. The mirror must be convex 
(c) There exist two angles of incidence in a prism for which angles of deviation are same except 
minimum deviation 
(d) A ray travels from a rarer medium to denser medium. There exist three angles of incidence for 
which the deviation is same 
Q 4.  A lens of focal length/is placed in between an object and screen at a distance D. The lens forms 
two real images of object on the screen for two of its different positions, a distance x apart. The 
two real images have magnifications m
1
 and m
2
 respectively (m
1
 > m
2
). Choose the correct 
statement(s). 
  (a) m
1
m
2
 = - 1   (b) m
1
m
2
 =1  (c) 
22
Dx
f
4D
?
?  (d) D ? 4f 
Page 2


For JEE Advanced 
More than One Correct Options 
 
Q 1.  n number of identical equilateral prisms are kept in contact as shown in figure. If deviation 
through a single prism is ?. Then (n, m are integers) 
 
  (a) if n = 2m, deviation through n prisms is zero 
  (b) if n = 2m + 1, deviation through system of n prisms is ? 
  (c) if n = 2m, deviation through system of n prisms is ? 
  (d) if n = 2m + 1, deviation through system of n prisms is zero 
Q 2.  A ray of monochromatic light is incident on the plane surface of separation between two media x 
and y with angle of incidence i in the mediumx and angle of refraction r in the medium y. The 
graph shows the relation between sin i and sin r 
 
  (a) The speed of light in the medium y is 3 times than in medium x 
  (b) The speed of light in the medium y is 
1
3
times than in medium x 
  (c) The total internal reflection can take place when the incidence is in x 
  (d) The total internal reflection can take place when the incidence is in y 
Q 3.  Which of the following statements is/are true? 
  (a) In vacuum the speed of red colour is more than that of violet color 
(b) An object in front of a mirror is moved towards the pole of a spherical mirror from infinity, it 
is found that image also moves towards the pole. The mirror must be convex 
(c) There exist two angles of incidence in a prism for which angles of deviation are same except 
minimum deviation 
(d) A ray travels from a rarer medium to denser medium. There exist three angles of incidence for 
which the deviation is same 
Q 4.  A lens of focal length/is placed in between an object and screen at a distance D. The lens forms 
two real images of object on the screen for two of its different positions, a distance x apart. The 
two real images have magnifications m
1
 and m
2
 respectively (m
1
 > m
2
). Choose the correct 
statement(s). 
  (a) m
1
m
2
 = - 1   (b) m
1
m
2
 =1  (c) 
22
Dx
f
4D
?
?  (d) D ? 4f 
Q 5.  A small angled prism of apex angle A =4° and refractive index ? = 1.5
 
is placed in front of a 
vertical plane mirror as shown in figure. If the mirror is rotated through an angle ? then the light 
ray becomes horizontal either after the mirror or after second time from the prism. The value of ? 
is 
 
  (a) 1°    (b) 2°   (c) 4°    (d) Not possible 
Answers 
1. (a,b) 2. (b,d) 3. (b,c) 4. (b,c,d) 5. (a,b) 
Solutions 
1.  For n = 2m, it is just like slab. 
   
  ?  Deviation = 0 
  For n = 2m+ 1, it is just like an identical prism of larger size. 
    
2.   
   
  Speed of light in medium-y is less. So, it is denser. T/R takes place when ray of travels 
from denser to rarer medium. 
3.  (a) If vacuum speed of light of all colours is same.  
  (b) 
  If object moves from to P then its virtual, erect and diminished image moves from F to P. 
Page 3


For JEE Advanced 
More than One Correct Options 
 
Q 1.  n number of identical equilateral prisms are kept in contact as shown in figure. If deviation 
through a single prism is ?. Then (n, m are integers) 
 
  (a) if n = 2m, deviation through n prisms is zero 
  (b) if n = 2m + 1, deviation through system of n prisms is ? 
  (c) if n = 2m, deviation through system of n prisms is ? 
  (d) if n = 2m + 1, deviation through system of n prisms is zero 
Q 2.  A ray of monochromatic light is incident on the plane surface of separation between two media x 
and y with angle of incidence i in the mediumx and angle of refraction r in the medium y. The 
graph shows the relation between sin i and sin r 
 
  (a) The speed of light in the medium y is 3 times than in medium x 
  (b) The speed of light in the medium y is 
1
3
times than in medium x 
  (c) The total internal reflection can take place when the incidence is in x 
  (d) The total internal reflection can take place when the incidence is in y 
Q 3.  Which of the following statements is/are true? 
  (a) In vacuum the speed of red colour is more than that of violet color 
(b) An object in front of a mirror is moved towards the pole of a spherical mirror from infinity, it 
is found that image also moves towards the pole. The mirror must be convex 
(c) There exist two angles of incidence in a prism for which angles of deviation are same except 
minimum deviation 
(d) A ray travels from a rarer medium to denser medium. There exist three angles of incidence for 
which the deviation is same 
Q 4.  A lens of focal length/is placed in between an object and screen at a distance D. The lens forms 
two real images of object on the screen for two of its different positions, a distance x apart. The 
two real images have magnifications m
1
 and m
2
 respectively (m
1
 > m
2
). Choose the correct 
statement(s). 
  (a) m
1
m
2
 = - 1   (b) m
1
m
2
 =1  (c) 
22
Dx
f
4D
?
?  (d) D ? 4f 
Q 5.  A small angled prism of apex angle A =4° and refractive index ? = 1.5
 
is placed in front of a 
vertical plane mirror as shown in figure. If the mirror is rotated through an angle ? then the light 
ray becomes horizontal either after the mirror or after second time from the prism. The value of ? 
is 
 
  (a) 1°    (b) 2°   (c) 4°    (d) Not possible 
Answers 
1. (a,b) 2. (b,d) 3. (b,c) 4. (b,c,d) 5. (a,b) 
Solutions 
1.  For n = 2m, it is just like slab. 
   
  ?  Deviation = 0 
  For n = 2m+ 1, it is just like an identical prism of larger size. 
    
2.   
   
  Speed of light in medium-y is less. So, it is denser. T/R takes place when ray of travels 
from denser to rarer medium. 
3.  (a) If vacuum speed of light of all colours is same.  
  (b) 
  If object moves from to P then its virtual, erect and diminished image moves from F to P. 
  (c) 
4.  Displacement method of finding focal length of convex lens. 
5.  Deviation ? = ( ? - 1) A = (1.5-1) 4° = 2°  
  (a) 
  To rotate ray MP by 2° (to make it parallel to MN) we will have to rotate the mirror only by 1°. 
(b) Without prism, ray of light was falling normal to plane mirror. So ray of light was retracing its 
path prism has deviated it 2°.  
So if we rotate the mirror by 2°, ray of light further falls normal to plan mirror and retraces its 
path. 
 
Match the Columns 
Q 1.  Match the following two columns for a convex lens corresponding to object position shown in 
column I. 
Column I Column II 
(a) Between O and F
1
 (p) Real 
(b) Between F
1
 and 2F
1
 (q) Virtual 
(c) Between O and F
2
 (r) Erect 
(d) Between F
2 
and 2F
2
 (s) Inverted 
  Note O ? optical centre, F
1
 ? first focus and F
2
 ? second focus. 
Q 2.  Match the following two columns for a concave lens corresponding to object position shown in 
column II. 
Column I Column II 
(a) Between O and F
1
 (p) Real 
(b) Between F
1
 and 2F
1
 (q) Virtual 
(c) Between O and F
2
 (r) Erect 
(d) Between F
2
 and 2F
2
 (s) Inverted 
Q 3.  Match the following two columns corresponding to single refraction from plane surface. In all 
cases shown in column I, ?
1
 > ?
2
.
 
 
Column I Column II 
Page 4


For JEE Advanced 
More than One Correct Options 
 
Q 1.  n number of identical equilateral prisms are kept in contact as shown in figure. If deviation 
through a single prism is ?. Then (n, m are integers) 
 
  (a) if n = 2m, deviation through n prisms is zero 
  (b) if n = 2m + 1, deviation through system of n prisms is ? 
  (c) if n = 2m, deviation through system of n prisms is ? 
  (d) if n = 2m + 1, deviation through system of n prisms is zero 
Q 2.  A ray of monochromatic light is incident on the plane surface of separation between two media x 
and y with angle of incidence i in the mediumx and angle of refraction r in the medium y. The 
graph shows the relation between sin i and sin r 
 
  (a) The speed of light in the medium y is 3 times than in medium x 
  (b) The speed of light in the medium y is 
1
3
times than in medium x 
  (c) The total internal reflection can take place when the incidence is in x 
  (d) The total internal reflection can take place when the incidence is in y 
Q 3.  Which of the following statements is/are true? 
  (a) In vacuum the speed of red colour is more than that of violet color 
(b) An object in front of a mirror is moved towards the pole of a spherical mirror from infinity, it 
is found that image also moves towards the pole. The mirror must be convex 
(c) There exist two angles of incidence in a prism for which angles of deviation are same except 
minimum deviation 
(d) A ray travels from a rarer medium to denser medium. There exist three angles of incidence for 
which the deviation is same 
Q 4.  A lens of focal length/is placed in between an object and screen at a distance D. The lens forms 
two real images of object on the screen for two of its different positions, a distance x apart. The 
two real images have magnifications m
1
 and m
2
 respectively (m
1
 > m
2
). Choose the correct 
statement(s). 
  (a) m
1
m
2
 = - 1   (b) m
1
m
2
 =1  (c) 
22
Dx
f
4D
?
?  (d) D ? 4f 
Q 5.  A small angled prism of apex angle A =4° and refractive index ? = 1.5
 
is placed in front of a 
vertical plane mirror as shown in figure. If the mirror is rotated through an angle ? then the light 
ray becomes horizontal either after the mirror or after second time from the prism. The value of ? 
is 
 
  (a) 1°    (b) 2°   (c) 4°    (d) Not possible 
Answers 
1. (a,b) 2. (b,d) 3. (b,c) 4. (b,c,d) 5. (a,b) 
Solutions 
1.  For n = 2m, it is just like slab. 
   
  ?  Deviation = 0 
  For n = 2m+ 1, it is just like an identical prism of larger size. 
    
2.   
   
  Speed of light in medium-y is less. So, it is denser. T/R takes place when ray of travels 
from denser to rarer medium. 
3.  (a) If vacuum speed of light of all colours is same.  
  (b) 
  If object moves from to P then its virtual, erect and diminished image moves from F to P. 
  (c) 
4.  Displacement method of finding focal length of convex lens. 
5.  Deviation ? = ( ? - 1) A = (1.5-1) 4° = 2°  
  (a) 
  To rotate ray MP by 2° (to make it parallel to MN) we will have to rotate the mirror only by 1°. 
(b) Without prism, ray of light was falling normal to plane mirror. So ray of light was retracing its 
path prism has deviated it 2°.  
So if we rotate the mirror by 2°, ray of light further falls normal to plan mirror and retraces its 
path. 
 
Match the Columns 
Q 1.  Match the following two columns for a convex lens corresponding to object position shown in 
column I. 
Column I Column II 
(a) Between O and F
1
 (p) Real 
(b) Between F
1
 and 2F
1
 (q) Virtual 
(c) Between O and F
2
 (r) Erect 
(d) Between F
2 
and 2F
2
 (s) Inverted 
  Note O ? optical centre, F
1
 ? first focus and F
2
 ? second focus. 
Q 2.  Match the following two columns for a concave lens corresponding to object position shown in 
column II. 
Column I Column II 
(a) Between O and F
1
 (p) Real 
(b) Between F
1
 and 2F
1
 (q) Virtual 
(c) Between O and F
2
 (r) Erect 
(d) Between F
2
 and 2F
2
 (s) Inverted 
Q 3.  Match the following two columns corresponding to single refraction from plane surface. In all 
cases shown in column I, ?
1
 > ?
2
.
 
 
Column I Column II 
(a) (p) Image distance greater than x from plane surface 
(b) (q) Image distance less than x from plane surface 
(c) 
(r) Real image 
(d) (s) Virtual image 
Q 4.  Match the following two columns. 
Column I Column II 
(a) 
(p) Real image 
(b) 
(q) Virtual image 
 
(c) 
(r) May be real or virtual image 
(d) 
(s) Image is at infinity 
Q 5.  A convex lens L
1
 and a concave lens L
2
 have refractive index 1.5. Match the following two 
columns. 
Column I Column II 
(a) L
1
 is immersed in a liquid of refractive index 1.4 (p) Lens will behave as convex lens 
(b) L
1
 is immersed in a liquid of refractive index 1.6 (q) Lens will behave as concave lens 
(c) L
2
 is immersed in a liquid of refractive index 1.4 (r) Magnitude of power of lens will increase 
(d) L
2
 is immersed in a liquid of refractive index 1.6 (s) Magnitude of power of lens will decrease 
Page 5


For JEE Advanced 
More than One Correct Options 
 
Q 1.  n number of identical equilateral prisms are kept in contact as shown in figure. If deviation 
through a single prism is ?. Then (n, m are integers) 
 
  (a) if n = 2m, deviation through n prisms is zero 
  (b) if n = 2m + 1, deviation through system of n prisms is ? 
  (c) if n = 2m, deviation through system of n prisms is ? 
  (d) if n = 2m + 1, deviation through system of n prisms is zero 
Q 2.  A ray of monochromatic light is incident on the plane surface of separation between two media x 
and y with angle of incidence i in the mediumx and angle of refraction r in the medium y. The 
graph shows the relation between sin i and sin r 
 
  (a) The speed of light in the medium y is 3 times than in medium x 
  (b) The speed of light in the medium y is 
1
3
times than in medium x 
  (c) The total internal reflection can take place when the incidence is in x 
  (d) The total internal reflection can take place when the incidence is in y 
Q 3.  Which of the following statements is/are true? 
  (a) In vacuum the speed of red colour is more than that of violet color 
(b) An object in front of a mirror is moved towards the pole of a spherical mirror from infinity, it 
is found that image also moves towards the pole. The mirror must be convex 
(c) There exist two angles of incidence in a prism for which angles of deviation are same except 
minimum deviation 
(d) A ray travels from a rarer medium to denser medium. There exist three angles of incidence for 
which the deviation is same 
Q 4.  A lens of focal length/is placed in between an object and screen at a distance D. The lens forms 
two real images of object on the screen for two of its different positions, a distance x apart. The 
two real images have magnifications m
1
 and m
2
 respectively (m
1
 > m
2
). Choose the correct 
statement(s). 
  (a) m
1
m
2
 = - 1   (b) m
1
m
2
 =1  (c) 
22
Dx
f
4D
?
?  (d) D ? 4f 
Q 5.  A small angled prism of apex angle A =4° and refractive index ? = 1.5
 
is placed in front of a 
vertical plane mirror as shown in figure. If the mirror is rotated through an angle ? then the light 
ray becomes horizontal either after the mirror or after second time from the prism. The value of ? 
is 
 
  (a) 1°    (b) 2°   (c) 4°    (d) Not possible 
Answers 
1. (a,b) 2. (b,d) 3. (b,c) 4. (b,c,d) 5. (a,b) 
Solutions 
1.  For n = 2m, it is just like slab. 
   
  ?  Deviation = 0 
  For n = 2m+ 1, it is just like an identical prism of larger size. 
    
2.   
   
  Speed of light in medium-y is less. So, it is denser. T/R takes place when ray of travels 
from denser to rarer medium. 
3.  (a) If vacuum speed of light of all colours is same.  
  (b) 
  If object moves from to P then its virtual, erect and diminished image moves from F to P. 
  (c) 
4.  Displacement method of finding focal length of convex lens. 
5.  Deviation ? = ( ? - 1) A = (1.5-1) 4° = 2°  
  (a) 
  To rotate ray MP by 2° (to make it parallel to MN) we will have to rotate the mirror only by 1°. 
(b) Without prism, ray of light was falling normal to plane mirror. So ray of light was retracing its 
path prism has deviated it 2°.  
So if we rotate the mirror by 2°, ray of light further falls normal to plan mirror and retraces its 
path. 
 
Match the Columns 
Q 1.  Match the following two columns for a convex lens corresponding to object position shown in 
column I. 
Column I Column II 
(a) Between O and F
1
 (p) Real 
(b) Between F
1
 and 2F
1
 (q) Virtual 
(c) Between O and F
2
 (r) Erect 
(d) Between F
2 
and 2F
2
 (s) Inverted 
  Note O ? optical centre, F
1
 ? first focus and F
2
 ? second focus. 
Q 2.  Match the following two columns for a concave lens corresponding to object position shown in 
column II. 
Column I Column II 
(a) Between O and F
1
 (p) Real 
(b) Between F
1
 and 2F
1
 (q) Virtual 
(c) Between O and F
2
 (r) Erect 
(d) Between F
2
 and 2F
2
 (s) Inverted 
Q 3.  Match the following two columns corresponding to single refraction from plane surface. In all 
cases shown in column I, ?
1
 > ?
2
.
 
 
Column I Column II 
(a) (p) Image distance greater than x from plane surface 
(b) (q) Image distance less than x from plane surface 
(c) 
(r) Real image 
(d) (s) Virtual image 
Q 4.  Match the following two columns. 
Column I Column II 
(a) 
(p) Real image 
(b) 
(q) Virtual image 
 
(c) 
(r) May be real or virtual image 
(d) 
(s) Image is at infinity 
Q 5.  A convex lens L
1
 and a concave lens L
2
 have refractive index 1.5. Match the following two 
columns. 
Column I Column II 
(a) L
1
 is immersed in a liquid of refractive index 1.4 (p) Lens will behave as convex lens 
(b) L
1
 is immersed in a liquid of refractive index 1.6 (q) Lens will behave as concave lens 
(c) L
2
 is immersed in a liquid of refractive index 1.4 (r) Magnitude of power of lens will increase 
(d) L
2
 is immersed in a liquid of refractive index 1.6 (s) Magnitude of power of lens will decrease 
Q 6.  Consider a linear extended object that could be real or virtual with its length at right angles to the 
optic axis of a lens. With regard to image formation by lenses. 
Column I Column II 
(a) Image of the same size as the object  (p) Concave lens in case of real object 
(b) Virtual image of a size greater than the object  (q) Convex lens in case of real object 
(c) Real image of a size smaller than the object  (r) Concave lens in case of virtual object 
(d) Real and magnified image \ (s) Convex lens in case of virtual object 
Answers 
  1. (a) ? q,r (b) ? p,s (c) ? p,r (d) ? p,r  2. (a) ? p,r (b) ? q,s (c) ? q,r (d) ? q,r 
  3. (a) ? q,s (b) ? q,r (c) ?p,s (d) ? p,r  4. (a) ? q (b) ? r (c) ? r (d) ? p   
  5. (a) ? p,s (b) ? q,s (c) ? q,s (d) ? p,s  6. (a) ? q,r (b) ? q,r (c) ? q,r (d) ? q,r 
Solutions 
1.  (c) and (d) 
   
  Between O and F
2
, or between F
2
 and 2F
2
, u is positive. So, v is also positive. 
   is positive 
  Therefore image is real (as v is positive) and erect (as m is also positive). 
2.  (a)  
   
  Between O and F
1
, u is positive and less than f. So, v is positive (therefore image is real). 
Further from 
    
  We can see that m is allow positive. So, it is erect also. 
  (b) 
   
  Between F
1
 and 2F
1
, ? positive and greater than f.  
  So, v negative (therefore image is virtual). Further from 
    
  We can see that m is negative so, image is inverted. 
3.  (a) and (b) 
    
  i.e.,v and u are of same sign. 
Or they are on same side of plane surface. From plane surface, if object is real, image is virtual 
and vice-versa.