NCERT Class 9 Science Solutions: Work and Energy Question: Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’. A wind-mill is lifting water from a well. Concept in a Minute: Work is done when a force causes a displacement in the […]

NCERT Class 9 Science Solutions: Tissues Question: Name the regions in which parenchyma tissue is present. Concept in a Minute: Parenchyma is a fundamental plant tissue found in various parts of plants. It consists of living cells with thin cell walls, involved in storage, photosynthesis, and secretion. Identifying regions where parenchyma is abundant is key.

NCERT Class 9 Science Solutions: The Fundamental Unit of Life Question: How do substances like CO2 and water move in and out of the cell? Discuss. Concept in a Minute: Cell membrane structure (fluid mosaic model), permeability (semi-permeable), and transport mechanisms (diffusion, osmosis, active transport). Explanation: Substances like CO2 and water move across the cell membrane

NCERT Class 9 Science Solutions: Structure of the Atom Question: Which one of the following is a correct electronic configuration of sodium? A. 2, 8 B. 8, 2, 1 C. 2, 1, 8 D. 2, 8, 1 Concept in a Minute: Electronic configuration describes the arrangement of electrons in different energy shells or orbitals of

NCERT Class 9 Science Solutions: Sound Question: Why are the ceilings of concert halls curved? Concept in a Minute: Sound reflection, specifically the principle of reflection where the angle of incidence equals the angle of reflection. Echoes and reverberation are also relevant. Explanation: The ceilings of concert halls are curved to ensure that sound waves

NCERT Class 9 Science Solutions: Motion Question: An athlete completes one round of a circular track of diameter 200 m in 40 s. What will be the distance covered and the displacement at the end of 2 minutes 20 s? Concept in a Minute: Circular motion, distance, displacement, speed, time, unit conversion. Distance is the

NCERT Class 9 Science Solutions: Matter in Our Surroundings Question: Why is ice at 273 K more effective in cooling than water at the same temperature? Concept in a Minute: The key concept here is the difference between sensible heat and latent heat. Sensible heat is the heat absorbed or released by a substance that

NCERT Class 9 Science Solutions: Is Matter Around Us Pure Question: Classify the following as chemical or physical change: Burning of paper and wood A. Chemical change B. Physical change Concept in a Minute: Physical change: A change in which the form or appearance of a substance changes, but its chemical composition remains the same.

NCERT Class 9 Science Solutions: Improvement in Food Resources Question: For increasing production, what is common in poultry, fisheries and bee-keeping? Concept in a Minute: Animal Husbandry: The management and breeding of domestic animals, especially livestock. This includes practices aimed at improving the yield of products like meat, milk, eggs, wool, honey, and fish. Key

NCERT Class 9 Science Solutions: Gravitation Question: What is the importance of the universal law of gravitation? Concept in a Minute: The universal law of gravitation describes the force of attraction between any two objects with mass. It’s crucial for understanding celestial motion, Earth’s gravity, and tides. Explanation: The importance of the universal law of