SOF ISO Sample Paper 2026 Class 12

CLASS

12
SAMPLE PAPER
2025-26 SOF NATIONAL
SCIENCE OLYMPIAD

Total Questions : 50 Time : 1 hr.
PATTERN & MARKING SCHEME
Section (1) Physics & Chemistry (2) Achievers Section (3) Mathematics
or
Biology
No. of Questions 25 5 20
Marks per Ques. 1 3 1

SYLLABUS
Section – 1 : Physics : Electricity and Magnetism, Electromagnetic Induction, Alternating current,
Electromagnetic waves, Optics, Modern Physics, Semiconductor Electronics.
Chemistry : Solutions, Electrochemistry, Chemical Kinetics, The d-and f-Block Elements,
Coordination Compounds, Haloalkanes and Haloarenes, Alcohols, Phenols and Ethers, Aldehydes,
Ketones and Carboxylic Acids, Amines, Biomolecules.
Section – 2 : Higher Order Thinking Questions - Syllabus as per Section – 1.
Section – 3 : Relations and Functions, Inverse Trigonometric Functions, Matrices and
Determinants, Continuity and Differentiability, Application of Derivatives, Integrals, Application of
Integrals, Differential Equations, Vector Algebra, Three Dimensional Geometry, Probability, Linear
Programming.
OR
Section – 3 : Reproduction, Genetics and Evolution, Biology in Human Welfare, Biotechnology,
Ecology.

PHYSICS AND CHEMISTRY
1. Match column I with column II and select the correct option.
Column I Column II
(Complex) (Hybridisation and magnetic moment)
(P) [Ni(CN)4]2– (I) sp3d2 and 4.89 B.M.
(Q) [CoF6]3– (II) d2sp3 and 0 B.M.
(R) [NiCl4] 2–
(III) dsp2 and 0 B.M.
(S) [Co(NH3)6]3+ (IV) sp3 and 2.83 B.M.
(A) (P) - (III), (Q) - (I), (R) - (II), (S) - (IV) (B) (P) - (III), (Q) - (I), (R) - (IV), (S) - (II)
(C) (P) - (IV), (Q) - (I), (R) - (III), (S) - (II) (D) (P) - (IV), (Q) - (II), (R) - (III), (S) - (I)
2. At 298 K, the values of Henry's law constant KH for the gases (P), (Q) and (R) in
water are given as 71.18, 1.67 and 41.85 kbar respectively.
Which of the given statements is/are not correct?
I. (P) has the highest solubility in water at a given pressure.
II. The pressure of a 55.5 molal solution of (Q) is 1.5 × 10–3 bar.

Sample Paper | Class-12 | 1

III. The solubility of (R) at 293 K is higher than that at 273 K.
(A) III only (B) II and III only (C) I and II only (D) I, II and III
3. The products (X) and (Y) obtained in the following reaction are
Br

(i) One eqv. Mg/Ether
(X) + (Y)
(ii) D2O

CH2Cl
D Br Br

(A) + DOMgCl (B) + HOMgCl (C) + DOMgCl (D) + DOMgCl

CH2Cl CH3 CH2D CH3

4. The given figure shows two point charges q and –q separated by a distance of
20 cm.
24 cm

q –q
10 cm 10 cm

What is the total electric flux passing through the circle?
8q 15q 16q
(A) (B) (C) (D) Zero
13ε0 38ε0 31ε0
P
1 L
5. The given figure shows a monochromatic point
source S emitting light of wavelength l = 500 S 0.5 mm
O
nm. A thin lens of circular shape and focal length
0.10 m is cut into two identical halves L1 and L2 L2
which are placed symmetrically about axis SO. 0.15 m 1.30 m
Here P is the point of third intensity maxima. Screen
Which one of the following statements is incorrect?
(A) If the gap between L1 and L2 is reduced from its original value of 0.5 mm, the
distance OP will increase.
(B) The distance of first maximum from the centre is 1.3 mm.
(C) The distance of fifth minimum from the centre is 1.5 mm.
(D) The distance of sixth maximum from the centre is 2 mm.
6. The peak emission from a black body at a certain temperature occurs at a
wavelength of 9000 Å. On increasing its temperature, the total radiation emitted
is increased 81 times. At the initial temperature, when the peak radiation from the
black body is incident on a metal surface, it does not cause any photo emission.
After the increase of temperature, the peak radiation from the black body caused
photo emission. To bring these photoelectrons to rest, a potential equivalent to
the excitation energy between n = 3 to n = 4, Bohr levels of hydrogen atom is
required. What is the work function of the metal?
(A) 3.48 eV (B) 2.25 eV (C) 6.92 eV (D) 5 eV

2 | Sample Paper | Class-12

ACHIEVERS SECTION
7. Study the following paragraph and fill in the blanks by selecting the correct
option.
Compound (P) has general formula C4H10O and gives immediate turbidity with
ZnCl2 and conc. HCl. When (P) is treated with 20% H3PO4 at 358 K, it produces
(Q) which on further reaction with acidic KMnO4 produces (R) . Ozonolysis of
(Q) produces (R) along with formaldehyde. (S) is a functional isomer of (R) .
(P) (Q) (R) (S)
(A) 2-methyl-propan-2-ol 2-methyl-prop-1-ene Butanal Butanone
(B) 2-methyl-propan-1-ol 2-Butene Butanone Butanal
(C) 2-methyl-propan-1-ol 1-Butene Propanal Propanone
(D) 2-methyl-propan-2-ol 2-methyl-prop-1-ene Propanone Propanal
8. A heavy nucleus P, at rest, undergoes fission in two lighter nuclei Q and R. Let
a = MP – MQ – MR, where MP , MQ and MR are the masses of P, Q and R respectively
and EQ and ER are the kinetic energies of Q and R respectively. The speeds of Q
and R are vQ and vR respectively. If c is the speed of light, which of the following
statements are correct?
 MQ  2 v Q MR
(i) EQ + ER = c2a (ii) EQ =  c α (iii) =
 MQ + MR  v R MQ

MQ MR
(iv) The magnitude of momentum for Q as well as R is c 2µα , where µ =
MQ + MR
(A) (i) and (ii) only
(B) (i), (iii) and (iv) only
(C) (iii) and (iv) only
(D) (i), (ii), (iii) and (iv)

MATHEMATICS

0 1 2  1/ 2 −1/ 2 1/ 2
  
–1 = −4 3 c  , then
9. If A =  1 2 3 and A 
 3 a 1 5 / 2 −3 / 2 1/ 2

(A) a = 2, c = 1/2
(B) a = 1, c = –1
(C) a = –1, c = 1
(D) a = 1/2, c = 1/2
   π
10. If the vectors a , b , c are such that each is inclined at an angle with the other
 3
    
and | a |=1, |b |= 2, | c |= 3, then | a + b + c | =
(A) 3 2 (B) 4
(C) 5 (D) 6

Sample Paper | Class-12 | 3

BIOLOGY
9. Refer to the given figure and select the incorrect statement regarding its parts
labelled as P-T.
T S
R

Q

P
(A) P consists of lutein cells, fibrin and blood clot.
(B) A large number of T degenerate during the phase from birth to puberty.
(C) R gets transformed into S which is characterised by a fluid filled cavity called
antrum.
(D) The primary oocyte completes its first meiotic division and is released as
haploid Q.
10. Given in the box are names of few species.
Lates niloticus, Eichhornia crassipes, Clarias gariepinus, Ectopistes migratorius,
Lantana camara, Blatta orientalis, Hydrodamalis gigas, Parthenium
hysterophous, Raphrus cucullatus
How many among them are extinct?
(A) 2 (B) 3 (C) 4 (D) 1

ANSWER KEY
Physics and Chemistry 1. (B) 2. (D) 3. (C) 4. (A) 5. (B) 6. (A) 7. (D) 8. (B)
Mathematics 9. (B) 10.(C)
Biology 9. (C) 10.(B)

4 | Sample Paper | Class-12