📘 HPBOSE Class 10 Science Practical Viva

Exam-Style Answers (Short, Clear & Scoring Format)

For Himachal Pradesh Board of School Education

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🔬 PHYSICS – Viva Answers

Q1. State Ohm’s Law.

Ans: At constant temperature, the current flowing through a conductor is directly proportional to the potential difference across its ends.

V \propto I \quad \Rightarrow \quad V = IR

Q2. SI unit of resistance?

Ans: Ohm (Ω)

Q3. Define focal length.

Ans: The distance between the optical centre of a lens and its principal focus is called focal length.

Q4. Define magnification.

Ans: Magnification is the ratio of height of image to height of object.

M = \frac{h_i}{h_o}

Q5. Define power of lens.

Ans: Power of lens is the reciprocal of focal length (in metre).

P = \frac{1}{f}

Q6. Real vs Virtual image (one line difference)

Ans: Real image can be obtained on screen; virtual image cannot be obtained on screen.

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🧪 CHEMISTRY – Viva Answers

Q1. What is pH?

Ans: pH is a scale used to measure acidity or basicity of a solution (range 0–14).

Q2. Define neutralization reaction.

Ans: A reaction in which acid reacts with base to form salt and water.

Example:

HCl + NaOH → NaCl + H_2O

Q3. Define oxidation and reduction.

Ans:

Oxidation – Addition of oxygen or removal of hydrogen.

Reduction – Removal of oxygen or addition of hydrogen.

Q4. Chemical formula of washing soda.

Ans: Na₂CO₃·10H₂O

Q5. What gas is released in electrolysis of water?

Ans: Hydrogen at cathode and oxygen at anode.

Q6. Define corrosion.

Ans: Slow eating away of metals due to reaction with air and moisture is called corrosion.

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🌿 BIOLOGY – Viva Answers

Q1. Define photosynthesis (with equation).

Ans: The process by which green plants prepare food in presence of sunlight and chlorophyll.

6CO_2 + 6H_2O \xrightarrow{sunlight} C_6H_{12}O_6 + 6O_2

Q2. Function of stomata.

Ans: Exchange of gases and loss of water through transpiration.

Q3. Define respiration.

Ans: The process of breaking down food to release energy is called respiration.

Q4. What is binary fission?

Ans: A type of asexual reproduction in which one organism divides into two equal parts.

Q5. What is reflex action?

Ans: Quick and automatic response to a stimulus controlled by spinal cord.

Q6. Name female reproductive hormone.

Ans: Estrogen and Progesterone.

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🎯 Viva Exam Tips (Scoring Method)

✔ Answer in 2–3 lines only

✔ Always write formula with unit

✔ Speak confidently

✔ Draw diagram if asked

✔ Use correct scientific terms