10th Science Half Portion Test

Take the final step toward mastering your mid-syllabus exams. This Class 10 Science Half Portion Test (Question Paper 3) is a comprehensive mock paper designed to challenge your critical thinking and core concepts. If you have already solved Papers 1 and 2, this third set will help you iron out any remaining weak spots, master your time management, and ensure you are 100% ready to handle any twist in the exam.

10TH SCIENCE - 2025-2026

STANDARD - X MARKS: 75

[Ln-4, 5, 6, 10, 11, 17, 18, 19, 20, 21, 22, 23]

I. Answer all the questions (12 × 1 = 12)

1. Kilowatt hour is the unit of
a) resistivity b) conductivity c) electrical energy d) electrical power

2. The frequency, which is audible to the human ear is
a) 50 kHz b) 20 kHz c) 15000 kHz d) 10000 kHz

3. _______ aprons are used to protect us from gamma radiations
a) Lead oxide b) Iron c) Lead d) Aluminium

4. Which of the following is not an "element + element → compound" type reaction?
a) C(s) + O₂(g) → CO₂(g) b) 2K(s) + Br₂(l) → 2KBr(s) c) 2CO(g) + O₂(g) → 2CO₂(g) d) 4Fe(s) + 3O₂(g) → 2Fe₂O₃(s)

5. The secondary suffix used in IUPAC nomenclature of an aldehyde is
a) -ol b) -oic acid c) -al d) -one

6. The large elongated cells that provide nutrition to developing sperms are
a) Primary germ cells b) Sertoli cells c) Leydig cells d) Spermatogonia

7. Okazaki fragments are joined together by
a) Helicase b) DNA polymerase c) RNA primer d) DNA ligase

8. The 'use and disuse theory' was proposed by
a) Charles Darwin b) Ernst Haeckel c) Jean Baptiste Lamarck d) Gregor Mendel

9. Pusa Komal is a disease resistant variety of
a) sugarcane b) rice c) cow pea d) maize

10. World 'No Tobacco Day' is observed on
a) May 31 b) June 6 c) April 22 d) October 2

11. The gases released from vehicles exhaust are
i. carbon monoxide ii. Sulphur dioxide iii. Oxides of nitrogen
a) i and ii b) i and iii c) ii and iii d) i, ii and iii

12. A renewable source of energy is
a) petroleum b) coal c) nuclear fuel d) tree

II. Answer any 7 questions (Qn. no - 22 compulsory) (7 × 2 = 14)

13. State Ohm's law.

14. Match:

a. Fe - 59	- Age of fossil
b. I - 131	- Leukemia
c. Na - 24	- Function of Heart
d. C - 14	- Thyroid disease

15. How does pH play an important role in everyday life?

16. Identify the parts A, B, C and D

17. What are allosomes?

18. Define genetic engineering.

19. What is metastasis?

20. What are the agents of soil erosion?

21. What is Sprite?

22. Calculate the amount of energy released when a radioactive substance undergoes fusion and results in a mass defect of 2 kg.

III. Answer any 7 questions (Qn. no - 32 compulsory) (7 × 4 = 28)

23.
a) What are the advantages of LED TV over the normal TV?
b) List the merits of LED bulb.

24. Differentiate soaps and detergents.

25.
a) How is the structure of DNA organised?
b) What is the biological significance of DNA?

26.
a) State the applications of DNA fingerprinting technique.
b) Differentiate between outbreeding and inbreeding.

27. What are the phases of menstrual cycle? Indicate the changes in the ovary and uterus

28. Define Ethnobotany and write its importance.

29.
a) Discuss the importance of biotechnology in the field of medicine.
b) Name two maize hybrids rich in amino acid lysine

30. How is a cancer cell different from a normal cell?

31. Enumerate the importance of forest.

32.
a) Lemon juice has a pH 2, what is the concentration of H⁺ ions?
b) Give the IUPAC name of the following compounds:
a) CH₃CH₂COCH₃
b) ClCH₂-CH₂-CH₂-CH₃

IV. Answer any 3 questions (3 × 7 = 21)

33.
i) a) What is meant by electric current?
b) Name and define its unit.
c) State Joule's law of heating.

(or)

ii) What is an echo?
a) State two conditions necessary for hearing an echo.
b) What are the medical applications of echo?
c) How can you calculate the speed of sound using echo?

34.
i) a) Explain the factors influencing the rate of a Reaction
b) Define combination reaction.

(or)

ii) The molecular formula of an alcohol is C₄H₁₀O. The locant number of its -OH group is 2.
a) Draw its structural formula.
b) Give its IUPAC name.
c) Is it saturated or unsaturated?

35.
i) With a neat labelled diagram describe the parts of a typical angiospermic ovule.

(or)

ii) a) Suggest measures to overcome the problems of an alcoholic.
b) What are psychotropic drugs?