CBSE Class 9 Sample Papers, Syllabus, Test Papers & NCERT Solutions

Question & Answer Science Exploration Class 9 – 2026 Question & Answer Class 9 Science Exploration Question & Answer Science Class 9 Old Book Question & Answer Class 9 Science

Revise, Reflect, Refine 1. Choose the most appropriate option to describe the role of biogeochemical cycles in an ecosystem. (i) To provide food directly to all organisms. (ii) To recycle essential nutrients between biotic and abiotic components. (iii) To create new elements for use by living things. (iv) To remove pollutants and toxins from the […]

Think It Over (Page No. 252) 1. How does the warming of Arabian Sea water affect the southwest monsoon in India? Answer: Warmer Arabian Sea water leads to increased evaporation from the sea surface. This extra moisture in the atmosphere causes fluctuations in the southwest monsoon, resulting in variable rainfall — bringing floods to some […]

Revise, Reflect, Refine 1. Meena and Hari observed an animal in their garden. Hari called it an insect while Meena said it was an earthworm. Choose the correct option which confirms that it is an insect. (i) Bilateral symmetrical body (ii) Body with jointed legs (iii) Cylindrical body (iv) Body with little segmentation Answer: (ii) […]

Think It Over (Page No. 228) 1. What do you understand by biodiversity? Answer: Biodiversity refers to the variety and variability of all living organisms on Earth. It includes diversity within species (genetic diversity), between species, and of ecosystems. For example, the wide range of plants, animals, fungi, and microorganisms living in different habitats — […]

Revise, Reflect, Refine 1. A flower’s anthers are removed before it matures. Later, pollen from another plant of the same species is dusted onto its stigma and seeds are produced. Which process has been ensured here? (i) Self-pollination (ii) Cross-pollination (iii) Fertilisation (iv) Tissue culture Answer: (ii) Cross-pollination Explanation: The anthers were removed before the […]

Think It Over (Page No. 208) 1. When does a farmer prefer asexual or sexual methods of reproduction for crops production? Answer: Asexual Reproduction is preferred when: The farmer wants to produce genetically identical plants with the same desirable traits, such as taste, yield, or disease resistance. Rapid, large-scale propagation is needed using methods like […]

Revise, Reflect, Refine 1. Which observation best supports the idea that sound is a mechanical wave? (i) Sound shows reflection (ii) Sound needs a medium to propagate (iii) Sound has frequency (iv) Sound carries energy Answer: (ii) Sound needs a medium to propagate Reason: A mechanical wave is defined as a wave that requires a […]

Think It Over (Page No. 184) 1. Two astronauts are repairing the arm of a space station together during a spacewalk. Can they talk to each other and hear the sounds of metal clanking as they do on the Earth? Answer: No, they cannot directly hear each other or the sounds of metal clanking during […]

Revise, Reflect, Refine 1. A particular element (A) has one electron in its third shell. There is another element (B) with six electrons in its second shell. (i) How many electrons does A tend to give or take to become stable? (ii) What kind of ion would it form? (iii) How many electrons does B […]

Think It Over (Page No. 162) 1. Water can be obtained from various sources. Are all these samples of water chemically identical? Answer: Yes, all samples of purified water are chemically identical, regardless of their source — whether from rivers, borewells, rainwater, or the ocean. This is explained by the Law of Constant Proportions (Proust’s […]

Revise, Reflect, Refine 1. Choose the correct options and explain the reason for the correct and incorrect options in the context of Ernest Rutherford’s gold foil experiment: (i) The experiment clearly showed the existence of neutrons in the nucleus. (ii) The results disproved the plum pudding model and led to the idea of a nucleus […]

Think It Over (Page No. 140) 1. Are atoms the smallest indivisible particles? Answer: No, atoms are not the smallest indivisible particles. Scientists discovered that atoms are made up of even smaller subatomic particles — electrons, protons, and neutrons. The discovery of electrons by J.J. Thomson (1897), protons by Rutherford, and neutrons by James Chadwick […]

Revise, Reflect, Refine 1. State whether True or False. (i) Work is said to be done when a force is applied, even if the object does not move. (ii) Lifting a bucket vertically upward results in positive work done on the bucket. (iii) The SI unit for both work and energy is joule (J). (iv) […]

Think It Over (Page No. 116) 1. What will be the magnitude of velocity of the child at the bottom of the blue slide? Answer: Using conservation of mechanical energy (ignoring friction), the potential energy at the top converts entirely to kinetic energy at the bottom: mgh=12mv2mgh = \frac{1}{2}mv^2 v=2ghv = \sqrt{2gh} So if the […]

Revise, Reflect, Refine 1. Using a horizontal force F, a table is moved across the floor at a constant velocity. How much is the frictional force exerted by the floor on the table? Answer: Since the table moves at constant velocity, acceleration = 0, so net force = 0. This means frictional force = applied […]

Think It Over (Page No. 94) 1. Why does a canoe move forward when the canoeist pushes water backwards with their paddle and why does it move faster when they push harder? Answer: By Newton’s 3rd Law, when the paddle pushes water backward, water pushes the paddle forward with equal and opposite force, moving the […]

Revise, Reflect, Refine 1. Which of the following mixtures are correctly classified as homogeneous (Hm) and heterogeneous (Ht)? Choose the correct option. (i) Air— Hm, Milk— Ht, Sugar solution— Hm, Smoke— Hm (ii) Brass— Ht, Fog— Ht, Vinegar— Ht, Muddy water— Hm (iii) Copper sulfate solution— Hm, Salt solution— Hm, Milk— Hm, Bronze— Hm (iv) Muddy water— Ht, Milk— Ht, Blood— Ht, Brass— Hm Answer: The correct answer is (iv) Muddy […]

Think It Over (Page No. 72) 1. Why do suspended particles settle in muddy water over time but not in milk? Answer: Muddy water is a suspension, where particles are large and heavy. Due to gravity, these particles settle down at the bottom when left undisturbed. Milk, on the other hand, is a colloid. Its […]

Revise, Reflect, Refine 1. My father went to a shop from home which is located at a distance of 250 m on a straight road. On reaching there, he discovered that he forgot to carry a cloth bag. He came home to take it, went to the shop again, bought provisions and came back home. […]