SOF NSO 2025 previous year paper practice · PYQ-pattern set

SOF NSO 2025 PYQ-pattern questions

Showing 10 of the 18 PYQ-pattern questions in this set — freshly worded in that year's pattern, not the original questions. Answers and solutions open under each question.

1. Q1 · Mathematical Operations

   If '+' means '×', '−' means '+', '×' means '÷' and '÷' means '−', then what is the value of: 16 + 4 − 8 × 2 ÷ 3?

   • A. 65
   • B. 67
   • C. 61
   • D. 63
   Answer and solution

   Answer: A

   Replacing symbols: 16×4 + 8÷2 − 3 = 64 + 4 − 3 = 65.

2. Q2 · Analogy

   Complete the analogy: 16 : 256 :: 12 : ?

   • A. 144
   • B. 132
   • C. 124
   • D. 120
   Answer and solution

   Answer: A

   16² = 256, similarly 12² = 144.

3. Q3 · Blood Relations

   Pointing to a woman, Ravi said, "She is the daughter of the only sister of my father's wife." How is the woman related to Ravi?

   • A. Sister
   • B. Cousin
   • C. Niece
   • D. Aunt
   Answer and solution

   Answer: B

   My father's wife = my mother. Only sister of my mother = my maternal aunt. Daughter of my maternal aunt = my cousin.

4. Q4 · Missing Characters

   Complete the series: A, D, G, J, ?

   • A. K
   • B. L
   • C. M
   • D. N
   Answer and solution

   Answer: C

   Each letter is 3 positions ahead of the previous one: A(+3)→D(+3)→G(+3)→J(+3)→M.

5. Q5 · Matter in Our Surroundings

   A student observes that when a balloon is filled with air and placed in a freezer for 30 minutes, it shrinks in size. Which property of matter is primarily responsible for this observation?

   • A. Matter is made up of tiny particles that are in constant motion
   • B. Particles of matter have negligible intermolecular space
   • C. Particles of matter attract each other with maximum force
   • D. Matter cannot change its state
   Answer and solution

   Answer: A

   On cooling, the kinetic energy of air particles decreases, causing them to move slower and come closer together, which reduces the volume of air inside the balloon.

6. Q6 · Force and Laws of Motion

   A force of 20 N acts on a body of mass 4 kg initially at rest. What will be the velocity of the body after 5 seconds?

   • A. 15 m/s
   • B. 20 m/s
   • C. 25 m/s
   • D. 30 m/s
   Answer and solution

   Answer: C

   Acceleration a = F/m = 20/4 = 5 m/s². Using v = u + at, where u = 0, we get v = 0 + 5×5 = 25 m/s.

7. Q7 · Atoms and Molecules

   What is the mass of 2 moles of calcium carbonate (CaCO₃)? [Given: Atomic masses - Ca = 40 u, C = 12 u, O = 16 u]

   • A. 100 g
   • B. 150 g
   • C. 200 g
   • D. 250 g
   Answer and solution

   Answer: C

   Molar mass of CaCO₃ = 40 + 12 + (3×16) = 100 g/mol. Mass of 2 moles = 2 × 100 = 200 g.

8. Q8 · Gravitation

   If the distance between two objects is doubled, the gravitational force between them becomes:

   • A. Half
   • B. One-fourth
   • C. Double
   • D. Four times
   Answer and solution

   Answer: B

   According to the universal law of gravitation, F ∝ 1/r². When distance is doubled, force becomes 1/(2r)² = 1/4 of the original value.

9. Q9 · Sound

   A sound wave travels with a speed of 340 m/s in air. If the wavelength of the wave is 0.68 m, what is the frequency of the sound?

   • A. 231 Hz
   • B. 500 Hz
   • C. 680 Hz
   • D. 1000 Hz
   Answer and solution

   Answer: B

   Frequency = Speed/Wavelength = 340/0.68 = 500 Hz.

10. Q10 · Why Do We Fall Ill

    Which of the following pairs of conditions correctly matches hypothyroidism and hyperthyroidism?

    • A. Hypothyroidism: High body temperature; Hyperthyroidism: Low body temperature
    • B. Hypothyroidism: Tendency towards obesity; Hyperthyroidism: Bulging of eyeballs
    • C. Hypothyroidism: Increased appetite; Hyperthyroidism: Low blood pressure
    • D. Hypothyroidism: Bulging of eyeballs; Hyperthyroidism: Tendency towards obesity
    Answer and solution

    Answer: B

    Hypothyroidism leads to weight gain and obesity tendency, while hyperthyroidism causes bulging of eyeballs (exophthalmos).