Paper 2

Q1

**Question:**  

Consider the following chemical equation:  

p Al + q H₂O → r Al₂O₃ + s H₂  

To balance this chemical equation, the values of ‘p’, ‘q’, ‘r’ and ‘s’ must be respectively:

Options

(A) 3, 2, 2, 1  

(B) 2, 3, 3, 1  

(C) 2, 3, 1, 3  

(D) 3, 1, 2, 2  

Answer (C) 2, 3, 1, 3  

Solution: Balanced equation is 2Al + 3H₂O → Al₂O₃ + 3H₂  

(Al: 2 = 2, H: 6 = 6, O: 3 = 3)

Q2

Question:

Which of the given option represents a family of salts?

Options:

(A) NaCl, Na₂SO₄, CaSO₄  

(B) K₂SO₄, Na₂SO₄, CaSO₄  

(C) NaNO₃, CaCO₃, Na₂CO₃  

(D) MgSO₄, CuSO₄, MgCl₂  

Answer: (B) K₂SO₄, Na₂SO₄, CaSO₄  

Solution: All three are sulphate salts (same anion SO₄²⁻) → they belong to the sulphate family of salts.

Q3

Question:

The most common method of extraction of metals from their oxide ores is:

Options:  

(A) Reduction with carbon  

(B) Reduction with hydrogen  

(C) Reduction with aluminium  

(D) Electrolytic reduction  

Answer: (A) Reduction with carbon  

Solution: Most oxide ores (like Fe₂O₃, ZnO, PbO etc.) are reduced using carbon (coke) in a blast furnace or furnace.

Q4

**Question:**  

Given below are the structures of some hydrocarbons. Select the two structures which are related to each other:

(i) H₃C–CH=CH–CH₃  

(ii) H₃C–CH₂–CH₂–CH₃  

(iii) H₃C–CH₂–CH₃  

(iv) Cl–CH₂–CH=CH₂  

**Options:**  

(A) (i) and (iv)  

(B) (ii) and (iv)  

(C) (ii) and (iii)  

(D) (i) and (iii)  

**Answer:** (C) (ii) and (iii)  

**Solution:** (ii) = butane, (iii) = propane → both are saturated alkanes (single bonds only) → belong to the same homologous series (alkanes).

### Q5

**Question:**  

Choose the incorrect statement about the common reaction used in hydrogenation of vegetable oils.

**Options:**  

(A) It is an addition reaction.  

(B) It takes place in the presence of nickel or palladium catalyst.  

(C) The product contains only single bonds between carbon atoms.  

(D) It is an addition reaction which occurs in the presence of an acid catalyst.  

**Answer:** (D)  

**Solution:** Hydrogenation of oils uses Ni or Pd catalyst (not acid catalyst). Acid catalyst is not used in this industrial process.

### Q6

**Question:**  

Match Column-I with Column-II and select the correct option:

Column-I  

a. Site of fertilisation of egg with the sperm  

b. Site of implantation of embryo  

c. Site of entry of sperm into the female reproductive tract  

d. Site through which waste materials generated by developing embryo are removed  

Column-II  

(i) Vagina (ii) Uterus (iii) Oviduct (iv) Placenta (v) Cervix  

**Options:**  

(A) a-(ii), b-(i), c-(v), d-(iv)  

(B) a-(iii), b-(i), c-(v), d-(iv)  

(C) a-(iv), b-(ii), c-(iii), d-(i)  

(D) a-(iii), b-(ii), c-(i), d-(iv)  

**Answer:** (D) a-(iii), b-(ii), c-(i), d-(iv)  

**Solution:** Fertilisation → Oviduct, Implantation → Uterus, Entry of sperm → Vagina, Waste exchange → Placenta.

### Q7

**Question:**  

The part of the brain which maintains the posture and balance of the body is:

**Options:**  

(A) Pons  

(B) Cerebrum  

(C) Cerebellum  

(D) Medulla  

**Answer:** (C) Cerebellum  

**Solution:** Cerebellum is responsible for coordination, posture, and balance of the body.

### Q8

**Question:**  

The plant hormone present in greater concentration in the areas of rapidly dividing cells is:

**Options:**  

(A) Auxin  

(B) Cytokinins  

(C) Gibberellins  

(D) Abscisic acid  

**Answer:** (B) Cytokinins  

**Solution:** Cytokinins promote cell division (cytokinesis) and are found in high concentration in meristematic tissues.

### Q9

**Question:**  

Select a pair of bisexual flowers from the following:

**Options:**  

(A) Papaya and mustard  

(B) Hibiscus and mustard  

(C) Hibiscus and papaya  

(D) Hibiscus and watermelon  

**Answer:** (B) Hibiscus and mustard  

**Solution:** Hibiscus (गुड़हल) and mustard (सरसों) both have male and female parts in the same flower → bisexual. Papaya and watermelon are unisexual.

### Q10

**Question:**  

The gastric glands present in the wall of the stomach release:

**Options:**  

(A) Mucus and Trypsin  

(B) Pepsin and Trypsin  

(C) Mucus and Pepsin  

(D) Pepsin and Salivary amylase  

**Answer:** (C) Mucus and Pepsin  

**Solution:** Stomach secretes mucus (protection) and pepsin (protein digestion). Trypsin is from pancreas, salivary amylase from salivary glands.

### Q11

**Question:**  

Absolute refractive index of water and glass is 4/3 and 3/2 respectively. If the speed of light in glass is 2 × 10⁸ m/s, the speed of light in water is:

**Options:**  

(A) 9/4 × 10⁸ m/s  

(B) 7/3 × 10⁸ m/s  

(C) 16/9 × 10⁸ m/s  

(D) 9/8 × 10⁸ m/s  

**Answer:** (A) 9/4 × 10⁸ m/s  

**Solution:**  

c = speed in vacuum = μ_glass × v_glass = (3/2) × 2×10⁸ = 3×10⁸ m/s  

v_water = c / μ_water = 3×10⁸ / (4/3) = (3×10⁸ × 3)/4 = 9/4 × 10⁸ m/s

### Q12

**Question:**  

When a beam of white light passes through a region of very fine dust particles, the colour of light that scatters the most in that region is:

**Options:**  

(A) red  

(B) orange  

(C) blue  

(D) yellow  

**Answer:** (C) blue  

**Solution:** Very fine particles scatter shorter wavelengths more (Rayleigh scattering) → violet/blue is scattered most (sky appears blue for same reason).

### Q13

**Question:**  

A wire of length 'l' is gradually stretched so that its length increases to 3l. If its original resistance is R, then its new resistance will be:

**Options:**  

(A) 3R  

(B) 6R  

(C) 9R  

(D) 27R  

**Answer:** (C) 9R  

**Solution:** R = ρL/A  

New length = 3L → new area = A/3 (volume constant)  

New R' = ρ(3L)/(A/3) = ρ(3L × 3)/A = 9 (ρL/A) = 9R

### Q14

**Question:**  

Which one of the following statements is not true about a bar magnet?

**Options:**  

(A) It sets itself in north-south direction when suspended freely.  

(B) It has attractive power for iron filings.  

(C) It produces magnetic field lines.  

(D) The direction of magnetic field lines inside a bar magnet is from its north pole to its south pole.  

**Answer:** (D)  

**Solution:** Inside a bar magnet, field lines go from **south pole to north pole** (not north to south). Outside → N to S.

### Q15

**Question:**  

The strength of magnetic field produced inside a long straight current carrying solenoid does not depend upon:

**Options:**  

(A) number of turns in the solenoid  

(B) direction of current flowing through the solenoid  

(C) material of the core filled inside the solenoid  

(D) radius of the coil of the solenoid  

**Answer:** (D) radius of the coil of the solenoid  

**Solution:** B = μ₀ n I (for air core) or B = μ n I (with core) → independent of radius for long solenoid.

Q16

**Question:**  

Other than the abiotic components, which of the given biotic components are **not** required to make an aquarium with small herbivorous fishes a self-sustaining system?  

(i) Aquatic plants and aquatic animals  

(ii) Terrestrial plants and terrestrial animals  

(iii) Decomposers as bacteria and fungi  

(iv) Consumers as clown fishes and sea urchins  

**Options:**  

(A) (i) and (iv)  

(B) (ii) and (iii)  

(C) (i) and (iii)  

(D) (ii) and (iv)  

**Answer:** (D) (ii) and (iv)  

**Solution:** A self-sustaining aquarium needs producers (aquatic plants), decomposers (bacteria/fungi), and primary consumers (herbivorous fish). Terrestrial plants/animals and marine consumers (clown fish, sea urchins) are not required in a freshwater herbivorous fish aquarium.

### Q17

**Question:**  

Assertion (A): Hydrogen gas is not evolved when a metal reacts with nitric acid.  

Reason (R): Nitric acid is a strong oxidising agent and oxidises the hydrogen produced in the reaction to water.  

**Options:**  

(A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).  

(B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).  

(C) Assertion (A) is true, but Reason (R) is false.  

(D) Assertion (A) is false, but Reason (R) is true.  

**Answer:** (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).  

**Solution:** Nitric acid (HNO₃) oxidises nascent hydrogen to water instead of allowing H₂ gas to escape, especially with dilute HNO₃ and most metals (except Mg/Mn in very dilute form).

### Q18

**Question:**  

Assertion (A): In our actions of writing or talking, our nervous system communicates with the muscles.  

Reason (R): Cranial nerves and spinal nerves form the peripheral nervous system.  

**Options:**  

(A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).  

(B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).  

(C) Assertion (A) is true, but Reason (R) is false.  

(D) Assertion (A) is false, but Reason (R) is true.  

**Answer:** (B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).  

**Solution:** Assertion is true (motor neurons from peripheral NS control muscles for writing/talking). Reason is true (cranial + spinal nerves = PNS), but it does not explain the communication mechanism — explanation involves motor/efferent neurons.

### Q19

**Question:**  

Assertion (A): Magnetic field lines around a bar magnet never intersect each other.  

Reason (R): Magnetic field produced by a bar magnet is a quantity that has both magnitude and direction.  

**Options:**  

(A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).  

(B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).  

(C) Assertion (A) is true, but Reason (R) is false.  

(D) Assertion (A) is false, but Reason (R) is true.  

**Answer:** (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).  

**Solution:** Magnetic field is a vector quantity (magnitude + direction). At any point, field has only one direction, so lines cannot intersect (two directions at one point impossible).

### Q20

**Question:**  

Assertion (A): Use of jute bags for shopping reduces pollution.  

Reason (R): Jute is biodegradable and its bag may be reused as and when needed.  

**Options:**  

(A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).  

(B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).  

(C) Assertion (A) is true, but Reason (R) is false.  

(D) Assertion (A) is false, but Reason (R) is true.  

**Answer:** (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).  

**Solution:** Jute bags are eco-friendly (biodegradable, reusable) → reduce plastic pollution and waste accumulation compared to non-biodegradable plastic bags.