NTSE Science - Physics, Chemistry & Biology

In electroplating, the object to be coated is made the cathode (negative electrode). Metal ions from the anode solution deposit onto the cathode surface.

By definition, hydrocarbons are organic compounds containing only carbon and hydrogen atoms (like methane, ethane, benzene). Oxygen, nitrogen, and CO2 are not defining components.

Chromium is the key component in heating element alloys like nichrome (nickel-chromium). Pure chromium isn't used alone, but among these options, it's the only element relevant to resistance heating alloys.

Fe3O4 is the chemical formula for Magnetite, a magnetic iron oxide. Hematite is Fe2O3, and Stone/Clay are not specific iron oxides.

The filament of the bulb has high melting point.

Coal is amorphous (non-crystalline) carbon. Diamond and Graphite are crystalline allotropes with ordered atomic structures.

A magnifying glass (convex lens) needs a short focal length to produce strong magnification - shorter focal length = higher magnification power.

Naphtha is a light petroleum fraction primarily used as a feedstock in petrochemical plants to produce ethylene and other chemicals through steam cracking. While jet engines use kerosene and automobile engines use gasoline or diesel, naphtha's main industrial application is in petrochemical manufacturing.

Bar is a unit of atmospheric pressure. Metric unit of atmospheric pressure equal to 14.50 pounds per square inch (lb/in2), 1.02 kilograms per square centimeter (kg/cm2), 29.53 inches of mercury (in Hg), or 0.9869 atmosphere. In engineering, the term 'bar gauge' (barG) is used to indicate that the pressure is read from a pressure gauge (which actually measures the difference between the fluid's pressure and the atmospheric pressure).

Sulphur dioxide (SO2) is classified as an acidic oxide because it reacts with water to form sulfurous acid (H2SO3). Acidic oxides are non-metal oxides that form acids when dissolved in water, unlike basic oxides which form bases.

Urea (NH2)2CO is a synthetic nitrogen fertilizer produced industrially through the Haber-Bosch process combining atmospheric nitrogen with hydrogen. Compost and humus are organic natural fertilizers, while urea is manufactured synthetically in chemical plants.

Optical fiber is used in endoscopy while treatment. Internal view of the body is seen while treating a person and that picture is taken on a computer, where a doctor can operate by seeing the picture.

Bronze is a metal alloy consisting primarily of copper, usually with tin as the main additive. It is hard and brittle.

Statistics is the branch of mathematics. All others are the branches of physics.

X-rays was discovered by Rontgen. That is why X-rays are also called as Rontgen radiation, after the name of scientist Wilhelm Conrad Rontgen, who is usually credited as its discoverer, and who had named it X-radiation to signify an unknown type of radiation.

Catla catla (catla), Labeo rohita (rohu), and Cirrhina mrigala (mrigal) are collectively known as Indian major carps and are all freshwater fish widely cultivated in aquaculture for food. All three are important edible fish species in South Asia.

Medicinal plant products are fundamental to all three traditional medicine systems mentioned - Ayurveda, Unani, and Siddha. These indigenous medical systems rely heavily on plant-based ingredients for their formulations and treatments.

Leprosy (Hansen's disease) is caused by the bacterium Mycobacterium leprae. It is a chronic infectious disease affecting skin and nerves, not caused by fungi, protozoa, or viruses.

Monazite sand is the primary commercial source of thorium, containing thorium oxide along with rare earth elements. Ilmenite is a titanium ore, pitchblende (uraninite) is a uranium ore, and galena is a lead ore.

Tea is a classical plantation crop grown on large estates primarily in tropical and subtropical regions. Plantation crops require specific climatic conditions and are commercially important export crops. Jute and cotton are fiber crops, while sugarcane is a cash crop but not typically classified as a plantation crop.

Fungi lack chlorophyll, the pigment essential for photosynthesis. This is why they cannot produce their own food through photosynthesis like plants and must obtain nutrients from external sources as heterotrophs. Presence of a clear nucleus and pigments (other than chlorophyll) are not the limiting factors.

Electromagnetic induction, discovered by Michael Faraday, is the principle behind electric generators. When a conductor moves through a magnetic field, it induces an electromotive force. Storage cells and dry cells store chemical energy, while testers measure electrical properties but don't generate it.