Class 10 Science: CBSE (Official) Marking Scheme with Solution- Term I (2021-22) | Science Class 10 PDF Download

 Page 1


Sample Question Paper (TERM – I) 2021-22 
Class X 
Science (086) 
 
Q.NO ANSWERS 
Section - A 
1. B. Yellow precipitate is formed 
2. B. Hydrogen 
3. D. ii and iv 
4. B. 3Fe(s) + 4H
2
O(g) ? Fe
3
O
4
 (s) + 4H
2
(g) 
5. D. D 
6. A. Fe and Fe respectively. 
7. C. Combination reaction 
8. 
 
9. A. By adding acid to water with constant stirring. 
10. C. To verify the Law of conservation of mass 
11. C. (iii) Alveoli: Thin-walled sac like structures for exchange of gases. 
12. B. (i) - amylase, (ii) - pepsin, (iii) - trypsin 
13. D. water content in the guard cells 
14. D. (iv) Vena cava takes blood from body parts to right auricle 
15. B. Blood is transferred to lungs for oxygenation and is pumped into various organs 
simultaneously. 
16. B. i.- b) ; ii – c) ; iii – d) ; iv- a) 
17. C. Concave mirror 
18. C. 
 
 
B H
2
CO
3
 Ca(OH) 
2
 
 
Page 2


Sample Question Paper (TERM – I) 2021-22 
Class X 
Science (086) 
 
Q.NO ANSWERS 
Section - A 
1. B. Yellow precipitate is formed 
2. B. Hydrogen 
3. D. ii and iv 
4. B. 3Fe(s) + 4H
2
O(g) ? Fe
3
O
4
 (s) + 4H
2
(g) 
5. D. D 
6. A. Fe and Fe respectively. 
7. C. Combination reaction 
8. 
 
9. A. By adding acid to water with constant stirring. 
10. C. To verify the Law of conservation of mass 
11. C. (iii) Alveoli: Thin-walled sac like structures for exchange of gases. 
12. B. (i) - amylase, (ii) - pepsin, (iii) - trypsin 
13. D. water content in the guard cells 
14. D. (iv) Vena cava takes blood from body parts to right auricle 
15. B. Blood is transferred to lungs for oxygenation and is pumped into various organs 
simultaneously. 
16. B. i.- b) ; ii – c) ; iii – d) ; iv- a) 
17. C. Concave mirror 
18. C. 
 
 
B H
2
CO
3
 Ca(OH) 
2
 
 
19. A. Concave mirror as well as convex lens 
20. C. The speed of light in air > the speed of light in water > the speed of light in glass. 
21. B. r > v 
22. B. The mirror has a focal length of -3 cm and will produce an image of magnification 
-1. 
23. B. 0° 
24. B. (ii) 
Section - B 
25. C. ?   ? ?
26. A. 2008 
27. B. Mg reacts with dil. HCl to produce H
2
 gas which helps in floating 
28. B. B, C 
29. B. ii and iii 
30. B. i and iv 
31. C. A is true but R is false 
32. D. A is False but R is true 
33. C. A is true but R is false. 
34. B. Both A and R are true and R is not the correct explanation of A. 
35. B. B and D 
36. D. Shark, dog fish, sting ray 
37. D. Thin walled capillaries richly supplied with blood. 
38. B. They selectively filter toxic substances through their leaves. 
39. C. concave lens of focal length -25 cm 
P = -4 D 
P = 
100 
?? ( ?? ?? ) 
f(cm) = 
100
 
?? 
100
  =  -25 cm. 
-4 
Negative focal length means concave lens. Concave lens of focal length -25cm. 
 
Page 3


Sample Question Paper (TERM – I) 2021-22 
Class X 
Science (086) 
 
Q.NO ANSWERS 
Section - A 
1. B. Yellow precipitate is formed 
2. B. Hydrogen 
3. D. ii and iv 
4. B. 3Fe(s) + 4H
2
O(g) ? Fe
3
O
4
 (s) + 4H
2
(g) 
5. D. D 
6. A. Fe and Fe respectively. 
7. C. Combination reaction 
8. 
 
9. A. By adding acid to water with constant stirring. 
10. C. To verify the Law of conservation of mass 
11. C. (iii) Alveoli: Thin-walled sac like structures for exchange of gases. 
12. B. (i) - amylase, (ii) - pepsin, (iii) - trypsin 
13. D. water content in the guard cells 
14. D. (iv) Vena cava takes blood from body parts to right auricle 
15. B. Blood is transferred to lungs for oxygenation and is pumped into various organs 
simultaneously. 
16. B. i.- b) ; ii – c) ; iii – d) ; iv- a) 
17. C. Concave mirror 
18. C. 
 
 
B H
2
CO
3
 Ca(OH) 
2
 
 
19. A. Concave mirror as well as convex lens 
20. C. The speed of light in air > the speed of light in water > the speed of light in glass. 
21. B. r > v 
22. B. The mirror has a focal length of -3 cm and will produce an image of magnification 
-1. 
23. B. 0° 
24. B. (ii) 
Section - B 
25. C. ?   ? ?
26. A. 2008 
27. B. Mg reacts with dil. HCl to produce H
2
 gas which helps in floating 
28. B. B, C 
29. B. ii and iii 
30. B. i and iv 
31. C. A is true but R is false 
32. D. A is False but R is true 
33. C. A is true but R is false. 
34. B. Both A and R are true and R is not the correct explanation of A. 
35. B. B and D 
36. D. Shark, dog fish, sting ray 
37. D. Thin walled capillaries richly supplied with blood. 
38. B. They selectively filter toxic substances through their leaves. 
39. C. concave lens of focal length -25 cm 
P = -4 D 
P = 
100 
?? ( ?? ?? ) 
f(cm) = 
100
 
?? 
100
  =  -25 cm. 
-4 
Negative focal length means concave lens. Concave lens of focal length -25cm. 
 
40. A. 30 cm in front of the mirror 
If rays converge at a point 15cm from the mirror, then, 
f = -15cm 
then, C = -30cm 
An object kept at C makes an image of the same size as object correct answer – 
(A) 30cm in front of mirror 
41. B. yeast, mushroom, bread mould 
42. D. Urine is more diluted. 
43. D. -80/3 cm 
m = -3 
V = 80cm 
m = 
?? 
?? 
-3 = 
80
 
?? 
u = 
80
 = 
-80
cm. 
-3 3 
Correct answer = (D) 
-80
cm. 
3 
44. C. ii, iii and iv 
45. D. Medium 1 and 3 are essentially the same medium, but medium 2 is denser than 
1 and 3 
46. B. 1.21 
Refractive index of flint glass w.r.t alcohol = 
?? . ?? 
?? ?? 
?? ?? ?? ?? ?? 
?? ?? ?? ?? ?? 
?? . ?? ?? ?? ?? ?? ?? ?? ? ?? ?? 
= 
1.65
 = 1.21 
1.36 
Correct answer –(B)1.21 
47. C. 4 mm 
f = +10cm (Convex lens) 
? 1= 2mm = 0.2cm. 
u = -5cm. 
1 
= 
1 
- 
1 
?? ?? 5 
1 
= 
1   
- 
1 
?? 10 5 
1-2 
= 
-1 
10 10 
V = -10cm. 
m= 
??  = 
? 2
 
?? ? 1 
m= 
-10 
= 
? 2 
-5 0.2 
? ? 2 = 0.4cm. 
?
2 
= 4mm 
 
Page 4


Sample Question Paper (TERM – I) 2021-22 
Class X 
Science (086) 
 
Q.NO ANSWERS 
Section - A 
1. B. Yellow precipitate is formed 
2. B. Hydrogen 
3. D. ii and iv 
4. B. 3Fe(s) + 4H
2
O(g) ? Fe
3
O
4
 (s) + 4H
2
(g) 
5. D. D 
6. A. Fe and Fe respectively. 
7. C. Combination reaction 
8. 
 
9. A. By adding acid to water with constant stirring. 
10. C. To verify the Law of conservation of mass 
11. C. (iii) Alveoli: Thin-walled sac like structures for exchange of gases. 
12. B. (i) - amylase, (ii) - pepsin, (iii) - trypsin 
13. D. water content in the guard cells 
14. D. (iv) Vena cava takes blood from body parts to right auricle 
15. B. Blood is transferred to lungs for oxygenation and is pumped into various organs 
simultaneously. 
16. B. i.- b) ; ii – c) ; iii – d) ; iv- a) 
17. C. Concave mirror 
18. C. 
 
 
B H
2
CO
3
 Ca(OH) 
2
 
 
19. A. Concave mirror as well as convex lens 
20. C. The speed of light in air > the speed of light in water > the speed of light in glass. 
21. B. r > v 
22. B. The mirror has a focal length of -3 cm and will produce an image of magnification 
-1. 
23. B. 0° 
24. B. (ii) 
Section - B 
25. C. ?   ? ?
26. A. 2008 
27. B. Mg reacts with dil. HCl to produce H
2
 gas which helps in floating 
28. B. B, C 
29. B. ii and iii 
30. B. i and iv 
31. C. A is true but R is false 
32. D. A is False but R is true 
33. C. A is true but R is false. 
34. B. Both A and R are true and R is not the correct explanation of A. 
35. B. B and D 
36. D. Shark, dog fish, sting ray 
37. D. Thin walled capillaries richly supplied with blood. 
38. B. They selectively filter toxic substances through their leaves. 
39. C. concave lens of focal length -25 cm 
P = -4 D 
P = 
100 
?? ( ?? ?? ) 
f(cm) = 
100
 
?? 
100
  =  -25 cm. 
-4 
Negative focal length means concave lens. Concave lens of focal length -25cm. 
 
40. A. 30 cm in front of the mirror 
If rays converge at a point 15cm from the mirror, then, 
f = -15cm 
then, C = -30cm 
An object kept at C makes an image of the same size as object correct answer – 
(A) 30cm in front of mirror 
41. B. yeast, mushroom, bread mould 
42. D. Urine is more diluted. 
43. D. -80/3 cm 
m = -3 
V = 80cm 
m = 
?? 
?? 
-3 = 
80
 
?? 
u = 
80
 = 
-80
cm. 
-3 3 
Correct answer = (D) 
-80
cm. 
3 
44. C. ii, iii and iv 
45. D. Medium 1 and 3 are essentially the same medium, but medium 2 is denser than 
1 and 3 
46. B. 1.21 
Refractive index of flint glass w.r.t alcohol = 
?? . ?? 
?? ?? 
?? ?? ?? ?? ?? 
?? ?? ?? ?? ?? 
?? . ?? ?? ?? ?? ?? ?? ?? ? ?? ?? 
= 
1.65
 = 1.21 
1.36 
Correct answer –(B)1.21 
47. C. 4 mm 
f = +10cm (Convex lens) 
? 1= 2mm = 0.2cm. 
u = -5cm. 
1 
= 
1 
- 
1 
?? ?? 5 
1 
= 
1   
- 
1 
?? 10 5 
1-2 
= 
-1 
10 10 
V = -10cm. 
m= 
??  = 
? 2
 
?? ? 1 
m= 
-10 
= 
? 2 
-5 0.2 
? ? 2 = 0.4cm. 
?
2 
= 4mm 
 
 
Correct answer (C) 4mm 
48. B. X, Y, Z 
Section - C 
49. C. CaCO
3
 
50. C. 18 g 
51. A. Brine 
52. A. Between 1 to 3 
53. C. Carbon dioxide 
54. B. Carbon dioxide 
55. B. Blue - black colour would be obtained on the leaf of plant Y and no change in 
colour on leaf of plant X. 
56. C. i. and iii 
57. B. a parallel-sided glass block 
58. C. 30
0
 
Refractive index of medium = 
sin
 
?? 
sin ?? 
1.5 = 
sin 48.6° 
sin ?? 
1.5 = 
0.75 
sin ?? 
sin ?? = 
0.75
 
0.5 
sin ?? =0.5 
r= sin
-1
(0.5) 
r= 30° 
Correct answer (C) 30° 
59. D. III and V are correct. 
60. A. lateral shift of the rays would have been less. 
 
*** 
Page 5


Sample Question Paper (TERM – I) 2021-22 
Class X 
Science (086) 
 
Q.NO ANSWERS 
Section - A 
1. B. Yellow precipitate is formed 
2. B. Hydrogen 
3. D. ii and iv 
4. B. 3Fe(s) + 4H
2
O(g) ? Fe
3
O
4
 (s) + 4H
2
(g) 
5. D. D 
6. A. Fe and Fe respectively. 
7. C. Combination reaction 
8. 
 
9. A. By adding acid to water with constant stirring. 
10. C. To verify the Law of conservation of mass 
11. C. (iii) Alveoli: Thin-walled sac like structures for exchange of gases. 
12. B. (i) - amylase, (ii) - pepsin, (iii) - trypsin 
13. D. water content in the guard cells 
14. D. (iv) Vena cava takes blood from body parts to right auricle 
15. B. Blood is transferred to lungs for oxygenation and is pumped into various organs 
simultaneously. 
16. B. i.- b) ; ii – c) ; iii – d) ; iv- a) 
17. C. Concave mirror 
18. C. 
 
 
B H
2
CO
3
 Ca(OH) 
2
 
 
19. A. Concave mirror as well as convex lens 
20. C. The speed of light in air > the speed of light in water > the speed of light in glass. 
21. B. r > v 
22. B. The mirror has a focal length of -3 cm and will produce an image of magnification 
-1. 
23. B. 0° 
24. B. (ii) 
Section - B 
25. C. ?   ? ?
26. A. 2008 
27. B. Mg reacts with dil. HCl to produce H
2
 gas which helps in floating 
28. B. B, C 
29. B. ii and iii 
30. B. i and iv 
31. C. A is true but R is false 
32. D. A is False but R is true 
33. C. A is true but R is false. 
34. B. Both A and R are true and R is not the correct explanation of A. 
35. B. B and D 
36. D. Shark, dog fish, sting ray 
37. D. Thin walled capillaries richly supplied with blood. 
38. B. They selectively filter toxic substances through their leaves. 
39. C. concave lens of focal length -25 cm 
P = -4 D 
P = 
100 
?? ( ?? ?? ) 
f(cm) = 
100
 
?? 
100
  =  -25 cm. 
-4 
Negative focal length means concave lens. Concave lens of focal length -25cm. 
 
40. A. 30 cm in front of the mirror 
If rays converge at a point 15cm from the mirror, then, 
f = -15cm 
then, C = -30cm 
An object kept at C makes an image of the same size as object correct answer – 
(A) 30cm in front of mirror 
41. B. yeast, mushroom, bread mould 
42. D. Urine is more diluted. 
43. D. -80/3 cm 
m = -3 
V = 80cm 
m = 
?? 
?? 
-3 = 
80
 
?? 
u = 
80
 = 
-80
cm. 
-3 3 
Correct answer = (D) 
-80
cm. 
3 
44. C. ii, iii and iv 
45. D. Medium 1 and 3 are essentially the same medium, but medium 2 is denser than 
1 and 3 
46. B. 1.21 
Refractive index of flint glass w.r.t alcohol = 
?? . ?? 
?? ?? 
?? ?? ?? ?? ?? 
?? ?? ?? ?? ?? 
?? . ?? ?? ?? ?? ?? ?? ?? ? ?? ?? 
= 
1.65
 = 1.21 
1.36 
Correct answer –(B)1.21 
47. C. 4 mm 
f = +10cm (Convex lens) 
? 1= 2mm = 0.2cm. 
u = -5cm. 
1 
= 
1 
- 
1 
?? ?? 5 
1 
= 
1   
- 
1 
?? 10 5 
1-2 
= 
-1 
10 10 
V = -10cm. 
m= 
??  = 
? 2
 
?? ? 1 
m= 
-10 
= 
? 2 
-5 0.2 
? ? 2 = 0.4cm. 
?
2 
= 4mm 
 
 
Correct answer (C) 4mm 
48. B. X, Y, Z 
Section - C 
49. C. CaCO
3
 
50. C. 18 g 
51. A. Brine 
52. A. Between 1 to 3 
53. C. Carbon dioxide 
54. B. Carbon dioxide 
55. B. Blue - black colour would be obtained on the leaf of plant Y and no change in 
colour on leaf of plant X. 
56. C. i. and iii 
57. B. a parallel-sided glass block 
58. C. 30
0
 
Refractive index of medium = 
sin
 
?? 
sin ?? 
1.5 = 
sin 48.6° 
sin ?? 
1.5 = 
0.75 
sin ?? 
sin ?? = 
0.75
 
0.5 
sin ?? =0.5 
r= sin
-1
(0.5) 
r= 30° 
Correct answer (C) 30° 
59. D. III and V are correct. 
60. A. lateral shift of the rays would have been less. 
 
*** 
Marking Scheme in lieu of diagram based questions for VI candidates 
Section - A 
2. B. Hydrogen 
3. D. Zinc 
5. B. Acidic 
11 A. Alveoli: Thin-walled sac like structures for exchange of gases. 
12 
 
14 
D. Vena cava - takes deoxygenated blood from body parts to right atrium 
15. B. Blood is transferred to lungs for oxygenation and is pumped into 
various organs simultaneously. 
16. B. i.- b) ; ii – c) ; iii – d) ; iv- a) 
18. C. It is a convex lens and the object is placed between pole and focus. 
22. B. The mirror will produce an image of magnification -1. 
23. B. 0° 
24. B. Violet. 
Section - B 
26. B. Rain water consists of dissolved oxides of sulphur. 
27. B. Mg reacts with dil. HCL to produce H
2
 gas which helps in floating. 
30. B. I and iv 
44. C. pass through the centre of curvature. 
45. D. glass is optically denser than water. 
47. C. 4 mm 
Section - C 
53. C. Carbon dioxide 
54. B. Carbon dioxide 
55. B. Blue - black colour would be obtained on the leaf of plant B 
56. C. i. and iii 
57. A. Dispersion 
58. B. Red colour is monochromatic. 
59. D. Different wavelengths travel at different speeds in the glass. 
60. C. Rainbow. 
 
*** 
 
L M N 
B amylase pepsin trypsin