Science Topper`s Answer Sheet - 2019, Class 10 | Extra Documents, Videos & Tests for Class 10 PDF Download

 Page 1


Topper's  
Answers
C.B.S.E.
2019
Class–X
Delhi/Outside Delhi Set
Science
Time : 3 Hours Max. Marks : 80
General Instructions :
 (i) The question paper comprises five Sections, A, B, C, D and E. You are to attempt All the sections.
 (ii)  All questions are Compulsory.
 (iii)  Internal choice is given in Sections B, C, D and E.
 (iv)  Questions number 1 and 2 in Section A are one-mark questions. They are to be answered in one word or in one sentence.
 (v)  Questions number 3 to 5 in Section B are two-marks questions. These are to be answered in about 30 words each.
 (vi)  Questions number 6 to 15 in Section C are three-marks questions. These are to be answered in about 50 words each.
 (vii)  Questions number 16 to 21 in Section D are five-marks questions. These are to be answered in about 70 words each.
 (viii)  Questions number 22 to 27 in Section E are based on practical skills. Each question is a two-marks question. These are to be 
 answered in brief.
Section – A
 1. State the S.I. unit of potential difference and name the device used to measure it. 1
Ans. 
 2. List two characteristics of a good fuel.  1
Ans. 
Section – B
 3. Draw a labelled ray diagram to show the path of the reflected ray corresponding to the ray which is directed 
towards the principal focus of a convex mirror. Mark the angle of incidence and angle of reflection on it. 2
Page 2


Topper's  
Answers
C.B.S.E.
2019
Class–X
Delhi/Outside Delhi Set
Science
Time : 3 Hours Max. Marks : 80
General Instructions :
 (i) The question paper comprises five Sections, A, B, C, D and E. You are to attempt All the sections.
 (ii)  All questions are Compulsory.
 (iii)  Internal choice is given in Sections B, C, D and E.
 (iv)  Questions number 1 and 2 in Section A are one-mark questions. They are to be answered in one word or in one sentence.
 (v)  Questions number 3 to 5 in Section B are two-marks questions. These are to be answered in about 30 words each.
 (vi)  Questions number 6 to 15 in Section C are three-marks questions. These are to be answered in about 50 words each.
 (vii)  Questions number 16 to 21 in Section D are five-marks questions. These are to be answered in about 70 words each.
 (viii)  Questions number 22 to 27 in Section E are based on practical skills. Each question is a two-marks question. These are to be 
 answered in brief.
Section – A
 1. State the S.I. unit of potential difference and name the device used to measure it. 1
Ans. 
 2. List two characteristics of a good fuel.  1
Ans. 
Section – B
 3. Draw a labelled ray diagram to show the path of the reflected ray corresponding to the ray which is directed 
towards the principal focus of a convex mirror. Mark the angle of incidence and angle of reflection on it. 2
2  ] Oswaal CBSE Topper's Answer – 2019, SCIENCE, Class – 10
Ans.
 
 4. List four properties of magnetic field lines.  2
Ans. 
  
 5. What is brine ? What happens when an electric current is passed through it ? Write chemical equation for it. 2
OR
  List the changes that are observed when dil. HCl is added to a small amount of copper oxide in a beaker. Write 
balanced chemical equation for the reaction.
Ans. 
Page 3


Topper's  
Answers
C.B.S.E.
2019
Class–X
Delhi/Outside Delhi Set
Science
Time : 3 Hours Max. Marks : 80
General Instructions :
 (i) The question paper comprises five Sections, A, B, C, D and E. You are to attempt All the sections.
 (ii)  All questions are Compulsory.
 (iii)  Internal choice is given in Sections B, C, D and E.
 (iv)  Questions number 1 and 2 in Section A are one-mark questions. They are to be answered in one word or in one sentence.
 (v)  Questions number 3 to 5 in Section B are two-marks questions. These are to be answered in about 30 words each.
 (vi)  Questions number 6 to 15 in Section C are three-marks questions. These are to be answered in about 50 words each.
 (vii)  Questions number 16 to 21 in Section D are five-marks questions. These are to be answered in about 70 words each.
 (viii)  Questions number 22 to 27 in Section E are based on practical skills. Each question is a two-marks question. These are to be 
 answered in brief.
Section – A
 1. State the S.I. unit of potential difference and name the device used to measure it. 1
Ans. 
 2. List two characteristics of a good fuel.  1
Ans. 
Section – B
 3. Draw a labelled ray diagram to show the path of the reflected ray corresponding to the ray which is directed 
towards the principal focus of a convex mirror. Mark the angle of incidence and angle of reflection on it. 2
2  ] Oswaal CBSE Topper's Answer – 2019, SCIENCE, Class – 10
Ans.
 
 4. List four properties of magnetic field lines.  2
Ans. 
  
 5. What is brine ? What happens when an electric current is passed through it ? Write chemical equation for it. 2
OR
  List the changes that are observed when dil. HCl is added to a small amount of copper oxide in a beaker. Write 
balanced chemical equation for the reaction.
Ans. 
Oswaal CBSE Topper's Answer – 2019, SCIENCE, Class – 10 [  3
  
  
Section – c 6. A concave mirror has a focal length of 20 cm. At what distance from the mirror should a 4 cm tall object be placed 
so that it forms an image at a distance of 30 cm from the mirror ? Also calculate the size of the image formed. 3
OR
  A real image 2/3rd of the size of an object is formed by a convex lens when the object is at a distance of 12 cm from 
it. Find the focal length of the lens.
Ans. 
Page 4


Topper's  
Answers
C.B.S.E.
2019
Class–X
Delhi/Outside Delhi Set
Science
Time : 3 Hours Max. Marks : 80
General Instructions :
 (i) The question paper comprises five Sections, A, B, C, D and E. You are to attempt All the sections.
 (ii)  All questions are Compulsory.
 (iii)  Internal choice is given in Sections B, C, D and E.
 (iv)  Questions number 1 and 2 in Section A are one-mark questions. They are to be answered in one word or in one sentence.
 (v)  Questions number 3 to 5 in Section B are two-marks questions. These are to be answered in about 30 words each.
 (vi)  Questions number 6 to 15 in Section C are three-marks questions. These are to be answered in about 50 words each.
 (vii)  Questions number 16 to 21 in Section D are five-marks questions. These are to be answered in about 70 words each.
 (viii)  Questions number 22 to 27 in Section E are based on practical skills. Each question is a two-marks question. These are to be 
 answered in brief.
Section – A
 1. State the S.I. unit of potential difference and name the device used to measure it. 1
Ans. 
 2. List two characteristics of a good fuel.  1
Ans. 
Section – B
 3. Draw a labelled ray diagram to show the path of the reflected ray corresponding to the ray which is directed 
towards the principal focus of a convex mirror. Mark the angle of incidence and angle of reflection on it. 2
2  ] Oswaal CBSE Topper's Answer – 2019, SCIENCE, Class – 10
Ans.
 
 4. List four properties of magnetic field lines.  2
Ans. 
  
 5. What is brine ? What happens when an electric current is passed through it ? Write chemical equation for it. 2
OR
  List the changes that are observed when dil. HCl is added to a small amount of copper oxide in a beaker. Write 
balanced chemical equation for the reaction.
Ans. 
Oswaal CBSE Topper's Answer – 2019, SCIENCE, Class – 10 [  3
  
  
Section – c 6. A concave mirror has a focal length of 20 cm. At what distance from the mirror should a 4 cm tall object be placed 
so that it forms an image at a distance of 30 cm from the mirror ? Also calculate the size of the image formed. 3
OR
  A real image 2/3rd of the size of an object is formed by a convex lens when the object is at a distance of 12 cm from 
it. Find the focal length of the lens.
Ans. 
4  ] Oswaal CBSE Topper's Answer – 2019, SCIENCE, Class – 10
  
  
 7. Draw the pattern of the field lines of the magnetic field around a current carrying straight conductor passing 
through and held perpendicular to a horizontal cardboard. State right-hand thumb rule and explain how this 
rule is useful to determine the direction of the magnetic field in the above case, if the direction of current in the 
conductor is vertically downwards.  3
Ans.
 
Page 5


Topper's  
Answers
C.B.S.E.
2019
Class–X
Delhi/Outside Delhi Set
Science
Time : 3 Hours Max. Marks : 80
General Instructions :
 (i) The question paper comprises five Sections, A, B, C, D and E. You are to attempt All the sections.
 (ii)  All questions are Compulsory.
 (iii)  Internal choice is given in Sections B, C, D and E.
 (iv)  Questions number 1 and 2 in Section A are one-mark questions. They are to be answered in one word or in one sentence.
 (v)  Questions number 3 to 5 in Section B are two-marks questions. These are to be answered in about 30 words each.
 (vi)  Questions number 6 to 15 in Section C are three-marks questions. These are to be answered in about 50 words each.
 (vii)  Questions number 16 to 21 in Section D are five-marks questions. These are to be answered in about 70 words each.
 (viii)  Questions number 22 to 27 in Section E are based on practical skills. Each question is a two-marks question. These are to be 
 answered in brief.
Section – A
 1. State the S.I. unit of potential difference and name the device used to measure it. 1
Ans. 
 2. List two characteristics of a good fuel.  1
Ans. 
Section – B
 3. Draw a labelled ray diagram to show the path of the reflected ray corresponding to the ray which is directed 
towards the principal focus of a convex mirror. Mark the angle of incidence and angle of reflection on it. 2
2  ] Oswaal CBSE Topper's Answer – 2019, SCIENCE, Class – 10
Ans.
 
 4. List four properties of magnetic field lines.  2
Ans. 
  
 5. What is brine ? What happens when an electric current is passed through it ? Write chemical equation for it. 2
OR
  List the changes that are observed when dil. HCl is added to a small amount of copper oxide in a beaker. Write 
balanced chemical equation for the reaction.
Ans. 
Oswaal CBSE Topper's Answer – 2019, SCIENCE, Class – 10 [  3
  
  
Section – c 6. A concave mirror has a focal length of 20 cm. At what distance from the mirror should a 4 cm tall object be placed 
so that it forms an image at a distance of 30 cm from the mirror ? Also calculate the size of the image formed. 3
OR
  A real image 2/3rd of the size of an object is formed by a convex lens when the object is at a distance of 12 cm from 
it. Find the focal length of the lens.
Ans. 
4  ] Oswaal CBSE Topper's Answer – 2019, SCIENCE, Class – 10
  
  
 7. Draw the pattern of the field lines of the magnetic field around a current carrying straight conductor passing 
through and held perpendicular to a horizontal cardboard. State right-hand thumb rule and explain how this 
rule is useful to determine the direction of the magnetic field in the above case, if the direction of current in the 
conductor is vertically downwards.  3
Ans.
 
Oswaal CBSE Topper's Answer – 2019, SCIENCE, Class – 10 [  5
  
 8. An ore on treatment with dil. HCl gives the smell of rotten egg. Name the type of this ore. How can the metal be 
obtained from its concentrated ore ?  3
Ans
.