⚛️ Science Question Paper with Solution 📖
📝 Section A: Physics & Chemistry
1. (A) Multiple Choice Questions (5 Marks)
- The device used for producing current is called a...
- At the time of a short circuit, the current in the circuit...
- The direction of the magnetic field around a straight conductor carrying current is given by...
- The relation between electricity and magnetism was first established by...
- The region around a magnet in which its force can be detected is called a...
1. (B) Multiple Choice Questions (5 Marks)
- The image formed by a concave mirror is...
- A concave mirror forms a virtual image of an object placed...
- A convex mirror always forms an image which is ... than the object size.
- No matter how far you stand from a spherical mirror, your image appears erect. The mirror may be...
- In the case of a concave mirror, an erect image is...
2. Attempt the Following (10 Marks)
1. ⚛️ Scientific Reason: Atomic size increases down a group.
- As we move down a group in the periodic table, the atomic number of the elements increases. This means elements lower in the group have more electrons.
- To accommodate these additional electrons, new electron shells are added to the atom.
- These new shells are farther from the nucleus, causing the distance to the outermost electrons (atomic radius) to increase. Therefore, the atomic size increases.
2. ⚗️ What is the importance of a chemical equation?
A chemical equation conveys the following key information:
- Reactants and products involved in the reaction.
- Symbols and formulae of all substances.
- Relative number of moles of reactants and products.
- Relative masses of reactants and products.
- Physical states (solid, liquid, gas, aqueous) of substances.
3. 🧪 Write short notes on Indicators (with examples).
Indicators are substances that change color to show the acidic or basic nature of a compound.
- Natural Indicators: Substances from nature like litmus, turmeric, red cabbage, and rose petals.
- Synthetic Indicators: Man-made chemicals like phenolphthalein and methyl orange.
- Olfactory Indicators: Substances whose odor changes in acidic or basic solutions, e.g., onion and clove oil.
- Universal Indicators: A mixture of several indicators that gives different colors at different pH values, allowing for an estimation of the pH.
4. ⚡️ Scientific Reason: The material used for a fuse has a low melting point.
- A fuse is a safety device connected in series with an electrical circuit to protect appliances from damage caused by excess current.
- When current flows, the fuse wire heats up (Joule's heating effect). If the current exceeds a safe limit (due to overloading or a short circuit), the heat generated must be sufficient to melt the fuse wire.
- By melting, the fuse breaks the circuit and stops the flow of the dangerously high current. For this to happen effectively, the material must have a low melting point.
5. 🧲 Define: Magnetic Field & Solenoid
- Magnetic Field: The region around a magnet or a current-carrying conductor where its magnetic influence (force of attraction or repulsion) can be experienced.
- Solenoid: A coil consisting of many turns of an insulated wire wrapped in the shape of a cylinder. When current passes through it, it behaves like a bar magnet.
🌿 Section B: Biology & Environmental Science
1. (A) & (B) Fill in the Blanks (10 Marks)
Complete the following statements with the correct terms.
Part 1
- In asexual mode of reproduction, the offspring are with minor differences.
- Both parents contribute an equal amount of genetic material to the offspring.
- Dominant character masks the recessive character.
- Selection by nature is not deliberate but progressive/natural.
- Mendel’s experiments were based on visible contrasting characters of garden peas (Pisum sativum).
Part 2
- A fragment of DNA that provides complete information about one protein is known as the gene for that protein.
- All children inherit an X chromosome from their mother.
- Sex determination in human beings is genetical.
- Fossils are collected from different levels of depths to determine their age.
- Minor differences occur in asexual reproduction due to small inaccuracies occurring in DNA copying.
2. Attempt the Following (10 Marks)
1. 💧 What are the functions of MPCB for preventing water pollution?
The Maharashtra Pollution Control Board (MPCB) has several functions, including:
- Planning comprehensive programs for pollution prevention, control, and abatement.
- Inspecting sewage and industrial effluent treatment plants and disposal facilities.
- Supporting and encouraging the development of pollution control technologies, waste recycling, and eco-friendly practices.
- Educating entrepreneurs on improving environmental performance.
- Creating public awareness and addressing public complaints regarding pollution.
2. ♻️ Define eco-efficiency and ways to achieve it.
Eco-efficiency is the creation of goods and services using fewer resources and creating less waste and pollution.
It can be achieved by:
- Using alternative raw materials: e.g., using agricultural residue instead of wood.
- Shifting to renewable energy: Using solar, wind, and hydropower.
- Adopting clean technology: Using devices like solar cookers or CNG in vehicles.
- Reusing and recycling waste: Processing materials like paper, glass, and plastic to make new products.
- Creating durable goods: Designing products that last longer and require fewer replacements.
3. 📢 What are the impacts of Noise pollution on the human body?
The effects of noise pollution depend on intensity, frequency, and duration of exposure. They can be categorized as:
- Auditory Effects: Temporary or permanent hearing loss (deafness), auditory fatigue.
- Non-auditory Effects: Annoyance, sleep disturbance, difficulty concentrating, interference with communication, and behavioral changes.
- Physiological Effects: Increased heart rate and blood pressure (hypertension), stress, anxiety, headaches, and other cardiovascular issues.
3. Attempt the Following (10 Marks)
1. 🧼 Differentiate between Detergents and Soaps.
| Feature | Detergents | Soaps |
|---|---|---|
| Chemical Nature | Ammonium or sulphonate salts of long-chain carboxylic acids. (Synthetic) | Sodium or potassium salts of long-chain fatty acids. (Natural) |
| Action in Hard Water | Effective. They do not form scum with calcium and magnesium ions. | Ineffective. They form insoluble scum, which reduces cleansing action. |
| Cleansing Action | Generally stronger and more effective than soaps. | Relatively weaker compared to detergents. |
| Biodegradability | Some are non-biodegradable and can cause water pollution. | Generally biodegradable and more environmentally friendly. |
2. 🧠 Explain the structure and function of a Nephron.
- The nephron is the basic structural and functional unit of the kidney, responsible for filtering blood and forming urine.
- It consists of a cup-shaped structure called the Bowman's capsule, which encloses a bundle of blood capillaries known as the glomerulus.
- Function: Blood enters the glomerulus under pressure, forcing water, salts, glucose, urea, and other small molecules into the Bowman's capsule. This initial fluid is called the glomerular filtrate.
- As the filtrate passes through the long tubule of the nephron, essential substances like glucose, amino acids, salts, and a major amount of water are selectively reabsorbed back into the blood.
- The remaining fluid, which contains waste products like urea, forms urine. The urine is collected in the collecting duct and eventually passed to the urinary bladder.
4. Attempt the Following (5 Marks)
1. 🐒 Explain Darwin's Theory of Natural Selection.
Charles Darwin's theory of evolution by natural selection is a cornerstone of modern biology. It is based on several key observations and inferences:
- Overproduction: Organisms produce more offspring than can possibly survive.
- Variation: There is natural variation within any population. Individuals are not identical.
- Struggle for Existence: Because of overproduction, there is a competition for limited resources like food, water, and shelter.
- Survival of the Fittest: Individuals with traits that are better suited (more "fit") for their environment are more likely to survive, reproduce, and pass on those advantageous traits to their offspring.
- Gradual Change: Over many generations, this process of natural selection leads to the accumulation of favorable traits in the population, which can eventually result in the formation of a new species (evolution).
In essence, nature "selects" the organisms that are best adapted to survive and reproduce in their particular environment.