TS Class 10 Physics Official Model Question Paper 2 with Solved Answers - Part-B

📋 Official Board Practice Series — Model Paper 2

TS SSC Physics Official Model Question Paper 2

Complete Solved 40-Mark Board Paper: Section I (2M Very Short), Section II (4M Short & Numericals), Section III (6M Essay Questions), Optics Diagrams & Part-B Objective MCQs

📌 Model Paper 2 Blueprint & Marks Allocation

1. Section I — Very Short (2M Each)

6 Direct Questions covering essential definitions, concepts, and unit conversions:

3 Questions Physics + 3 Questions Chemistry = 12 Marks

2. Section II — Short & Numericals (4M Each)

4 Problem-solving and procedural questions with step-by-step calculations:

2 Physics Numericals + 2 Chemistry Processes = 16 Marks

3. Section III — Essay & Choice (6M Each)

2 High-weightage essay questions with internal choice, ray diagrams, and experiments:

1 Physics Essay + 1 Chemistry Essay = 12 Marks

📊 Key High-Weightage Topics Covered in Model Paper 2

Targeted core concepts curated according to the latest SCERT Telangana Board Examination Pattern:

High Priority Chapters in Model Paper 2

1. Total Internal Reflection & Lenses

Focus: Critical angle formula n = 1/sin(C), lens magnification m = v/u, and optical fibers.

2. Series Resistors & Power Bill

Focus: Series circuit calculations, potential drops, and kWh monthly power energy bill calculations.

3. Acids, Bases & Quantum Numbers

Focus: pH scale in stomach/teeth and 4 quantum numbers for 4s¹ electron of Potassium (K, Z = 19).

4. Periodic Table & Organic Chemistry

Focus: Periodic trends (Atomic size, IE, EN) across periods/groups and Saponification reaction.

Valuation Tip: Write proper units (Tesla, Weber, Ohm, Volt, Watt), draw clean ray diagrams with arrows, and state balanced chemical equations with state symbols to score full marks.

📝 Section I: Very Short Answer Questions (2 Marks Each)

QUESTION 1 - 2 MARKS (PHYSICS)

Q1. Define Critical Angle and Total Internal Reflection. Write the formula connecting Critical Angle (C) and Refractive Index (n).

Answer:

• Critical Angle (C): The angle of incidence in a denser medium for which the angle of refraction in the rarer medium becomes exactly 90°.
• Total Internal Reflection: When light travels from a denser to a rarer medium at an angle of incidence greater than the critical angle, the entire light reflects back into the denser medium.
• Formula: n = 1 / sin(C)   or   sin(C) = 1 / n

QUESTION 2 - 2 MARKS (PHYSICS)

Q2. Calculate the focal length of a lens having a power of -2.5 D. What type of lens is it?

Given: Power P = -2.5 D

Formula: Focal length f = 100 / P (in cm)

f = 100 / (-2.5) = -40 cm

✓ Final Answer: Focal length f = -40 cm. Negative sign indicates it is a Concave Lens (Diverging Lens).

QUESTION 3 - 2 MARKS (PHYSICS)

Q3. State Faraday's Law of Electromagnetic Induction.

Answer:

• Faraday's Law: Whenever there is a continuous change in the magnetic flux linked with a closed coil, an induced electromotive force (EMF) and current are produced in the coil.
• The magnitude of the induced EMF is directly proportional to the rate of change of magnetic flux linked with the circuit:
  ε = - ΔΦ / Δt

QUESTION 4 - 2 MARKS (CHEMISTRY)

Q4. Write the set of four Quantum Numbers for the 17th electron of Chlorine (Cl, Z = 17).

Answer:

• Chlorine (Cl, Z = 17): Configuration = 1s² 2s² 2p⁶ 3s² 3p⁵. The 17th electron enters the 3p subshell.
• 4 Quantum Numbers:
  • Principal Quantum Number (n) = 3
  • Angular Momentum Quantum Number (l) = 1 (p-subshell)
  • Magnetic Quantum Number (m_l) = 0 (or +1 / -1)
  • Spin Quantum Number (m_s) = -½ (paired spin)

QUESTION 5 - 2 MARKS (CHEMISTRY)

Q5. Why does tooth decay start when mouth pH falls below 5.5? How can it be prevented?

Answer:

• Reason: Tooth enamel is made of Calcium Phosphate (hardest substance in the body). When mouth pH drops below 5.5, the acid produced by oral bacteria degrading leftover sugar particles corrodes and dissolves the enamel.
• Prevention: Brushing teeth after meals using alkaline toothpaste neutralizes excess mouth acid and prevents decay.

QUESTION 6 - 2 MARKS (CHEMISTRY)

Q6. What is Saponification? Write the chemical equation for the preparation of soap.

Answer:

• Saponification: The process of hydrolyzing an ester (fat or oil) by heating it with an aqueous strong base like Sodium Hydroxide (NaOH) to prepare Soap.
• Chemical Equation:
  CH₃COOC₂H₅ (Ester) + NaOH → CH₃COONa (Soap) + C₂H₅OH (Alcohol)

🧮 Section II: Short Answer Questions & Solved Numericals (4 Marks Each)

QUESTION 7 - 4 MARKS (PHYSICS NUMERICAL)

Q7. Three resistors of 10 Ω, 20 Ω, and 30 Ω are connected in series across a 12 V battery. Calculate:
(a) Equivalent resistance of the series circuit.
(b) Total current flowing through the circuit.
(c) Potential difference (voltage drop) across the 10 Ω resistor.

Given Data: R₁ = 10 Ω, R₂ = 20 Ω, R₃ = 30 Ω, Voltage V = 12 V

(a) Calculating Equivalent Resistance (R_eq) in Series:

R_eq = R₁ + R₂ + R₃ = 10 + 20 + 30 = 60 Ω

(b) Calculating Total Circuit Current (I):

I = V / R_eq = 12 V / 60 Ω = 0.2 A

(c) Calculating Voltage Drop across 10 Ω Resistor (V₁):

V₁ = I × R₁ = 0.2 A × 10 Ω = 2 V

✓ Final Result:
1. Equivalent Resistance R_eq = 60 Ω.
2. Total Circuit Current I = 0.2 A.
3. Potential Difference across 10 Ω = 2 V.

QUESTION 8 - 4 MARKS (PHYSICS OPTICS NUMERICAL)

Q8. A convex lens forms a real inverted image at a distance of 30 cm from the lens for an object placed at a distance of 15 cm in front of it. Calculate:
(a) Focal length of the lens (f).
(b) Magnification (m) produced by the lens.

Given Data (Sign Convention): Object distance u = -15 cm | Image distance v = +30 cm (Real image)

(a) Calculating Focal Length (f) using Lens Formula (1/f = 1/v - 1/u):

1 / f = 1 / 30 - 1 / (-15) = 1 / 30 + 1 / 15 = (1 + 2) / 30 = 3 / 30 = 1 / 10

f = +10 cm

(b) Calculating Magnification (m):

m = v / u = (+30) / (-15) = -2

✓ Final Answer:
1. Focal Length f = +10 cm (Convex Lens).
2. Magnification m = -2 (Image is real, inverted, and magnified 2 times).

QUESTION 9 - 4 MARKS (CHEMISTRY)

Q9. Describe the Froth Floatation process for concentrating sulphide ores with a neat principle and process explanation.

Answer:

• Principle: Based on the difference in wetting properties of ore particles and gangue impurities. Ore particles are preferentially wetted by pine oil, while gangue particles are wetted by water.
• Operational Procedure:
  1. Finely crushed sulphide ore (e.g., Galena PbS or Zinc Blende ZnS) is mixed with water and pine oil in a large flotation tank.
  2. Compressed air is blown through a pipe to agitate the mixture and generate rich froth.
  3. Light sulphide ore particles adhere to pine oil bubbles and float to the surface as froth, which is skimmed off and dried. Heavy gangue settles at the bottom.

QUESTION 10 - 4 MARKS (CHEMISTRY)

Q10. Write the IUPAC names, structural formulas, and functional groups for the following organic compounds:
(a) CH₃CH₂OH
(b) CH₃COOH
(c) CH₃COCH₃
(d) CH₃CHO

Formula	Functional Group	IUPAC Name	Common Name
CH3CH2OH	Alcohol (−OH)	Ethanol	Ethyl Alcohol
CH3COOH	Carboxylic Acid (−COOH)	Ethanoic Acid	Acetic Acid
CH3COCH3	Ketone (>C=O)	Propanone	Acetone
CH3CHO	Aldehyde (−CHO)	Ethanal	Acetaldehyde

📑 Section III: Essay Type Questions & Ray Diagrams (6 Marks Each)

QUESTION 11 (A) - 6 MARKS (PHYSICS ESSAY)

Q11 (A). An object is placed at 2F₁ (Center of Curvature) in front of a Convex Lens. Describe the position, nature, size, and magnification of the image formed. Draw a schematic ray diagram.

Answer:

• Position of Object: At 2F₁ in front of the convex lens.
• Position of Image: Formed exactly at 2F₂ on the opposite side of the lens.
• Nature and Characteristics of Image:
  1. Nature: Real and Inverted.
  2. Size: Same size as the object.
  3. Magnification (m): m = -1 (Negative sign indicates inverted image).

Ray Tracing Rules Used:

1. Ray 1: Parallel to principal axis refracts through focus F₂.

2. Ray 2: Passing through Optic Center O continues straight undeviated.

3. Intersection Point: Both refracted rays intersect at 2F₂ to form the real inverted image.

QUESTION 11 (B) - 6 MARKS (ALTERNATIVE ESSAY)

Q11 (B). Explain the defect of vision Myopia (Nearsightedness). State its causes and explain how it can be corrected using a Concave Lens with a formula for focal length.

Answer:

• Myopia: A defect of vision in which a person can see nearby objects clearly, but cannot see distant objects distinctly because the image of a distant object forms in front of the retina rather than on it.
• Causes of Myopia:
  1. Elongation of the eyeball from front to back.
  2. Excessive curvature of the eye lens (focal length becomes too short).
• Correction using Concave Lens: A concave lens of suitable focal length diverges parallel light rays coming from a distant object so that they appear to diverge from the eye's far point (D) and focus precisely on the retina.
• Focal Length Formula:
  f = -D (where D is the distance of the far point of the myopic eye).

QUESTION 12 - 6 MARKS (CHEMISTRY ESSAY)

Q12. Explain the trends of Atomic Radius, Ionization Energy, and Electronegativity across a Period (Left to Right) and down a Group (Top to Bottom) in the Modern Periodic Table with justifications.

Answer:

Periodic Property	Across a Period (Left to Right)	Down a Group (Top to Bottom)
1. Atomic Radius	Decreases: Nuclear charge increases while principal energy shell remains constant, pulling valence electrons tighter toward the nucleus.	Increases: New principal energy shells are added at each successive step, expanding atomic size.
2. Ionization Energy (IE)	Increases: Smaller atomic radius increases the electrostatic nuclear attraction on valence electrons, requiring higher energy to remove an electron.	Decreases: Outer electrons are farther from the nucleus and shielded by inner shell electrons, making them easier to remove.
3. Electronegativity (EN)	Increases: Stronger nuclear pull enhances the ability to attract shared electron pairs in a covalent bond (Fluorine EN = 4.0).	Decreases: Larger atomic size weakens nuclear attraction on bonded electron pairs.

🎯 PART-B Objective Bits Bank (10 MCQs - Model Paper 2)

BIT 1

1. The focal length of a concave lens is -20 cm. Its power in dioptres is:

• -5.0 D
• +5.0 D
• -2.0 D
• +0.2 D

✓ Correct Option: A (P = 100 / f = 100 / -20 = -5.0 D)

BIT 2

2. What ray passes undeviated through a lens?

• Ray parallel to principal axis
• Ray passing through Optic Center (O)
• Ray passing through Focus (F)
• Ray at 45° angle

✓ Correct Option: B (Ray passing through Optic Center)

BIT 3

3. What is the SI unit of Magnetic Flux (Φ)?

• Tesla
• Weber
• Ohm
• Volt

✓ Correct Option: B (Weber - Wb)

BIT 4

4. Fleming's Right Hand Rule determines the direction of:

• Magnetic Force
• Induced Current
• Electric Field
• Resistance

✓ Correct Option: B (Induced Current in a Generator)

BIT 5

5. Maximum electron capacity of a d-subshell is:

• 2
• 6
• 10
• 14

✓ Correct Option: C (10 electrons)

BIT 6

6. Tooth decay begins when mouth pH drops below:

• 7.0
• 6.5
• 5.5
• 4.0

✓ Correct Option: C (pH below 5.5)

BIT 7

7. What is the chemical formula of Cinnabar (ore of Mercury)?

• HgO
• HgS
• PbS
• ZnS

✓ Correct Option: B (HgS)

BIT 8

8. Modern Periodic Law states that properties of elements are periodic functions of their:

• Atomic mass
• Atomic number
• Mass number
• Valency

✓ Correct Option: B (Atomic Number)

BIT 9

9. General formula of Alkyne hydrocarbons containing a triple bond is:

• C_nH_2n+2
• C_nH_2n
• C_nH_2n-2
• C_nH_2n+1

✓ Correct Option: C (C_nH_2n-2)

BIT 10

10. The functional group present in Propanone (Acetone) is:

• Alcohol (−OH)
• Aldehyde (−CHO)
• Ketone (>C=O)
• Carboxylic Acid (−COOH)

✓ Correct Option: C (Ketone >C=O)