General Science Mixed Quiz: Set 205

This is the law of conservation of energy: energy only changes from one form to another. In any isolated system the total energy stays the same.

Each kidney contains about a million nephrons, and each nephron consists of a Bowman's capsule enclosing a knot of capillaries called the glomerulus, followed by a tubule in which useful substances are reabsorbed; together they filter the blood and form urine.

Light slows down when it enters water from air, so a ray that strikes the surface at an angle bends towards the normal.

The lotus, declared the national flower of India, is Nelumbo nucifera, an aquatic plant rooted in the mud of ponds and tanks with leaves and flowers held above the water, and it carries a long place in Indian art and religion.

A microphone is a transducer that changes the pressure variations of sound into a matching electrical signal. In a common dynamic microphone, sound waves make a thin diaphragm vibrate.

Ornithology is the study of birds, their classification, habits, migration and nesting; Salim Ali, known as the birdman of India, was the country's best known ornithologist and wrote the Book of Indian Birds.

Both particles gain the same kinetic energy, but the electron is far lighter, so it ends up much faster. When a charge q is accelerated through a potential difference V, it gains kinetic energy equal to qV.

In a pair of tongs the joint is the fulcrum, the hand presses somewhere in the middle of the arms and the object held lies at the far end, so the effort is between the fulcrum and the load; the effort arm is shorter than the load arm, the mechanical…

Zinc oxide is amphoteric: it reacts with acids as a base and with strong alkalis as an acid, giving a salt and water in both cases.

These bicarbonates are formed when water containing dissolved carbon dioxide passes over limestone, and they are unstable; on boiling they lose carbon dioxide and settle as insoluble carbonates, which is why this kind of hardness is called temporary and can be removed by boiling alone, or by the Clark method…

Bleaching powder is calcium oxychloride, CaOCl₂, and DDT is dichlorodiphenyltrichloroethane; chlorine is the one element common to both. Bleaching powder is made by passing chlorine gas over dry slaked lime.

The stapes, also called the stirrup because of its shape, lies in the middle ear and is the smallest bone in the human body; it passes the vibration received from the eardrum on to the oval window of the inner ear.

Lysosomes are small membrane-bound sacs full of hydrolytic enzymes that digest worn-out parts and foreign material inside the cell. Lysosomes are formed from the Golgi apparatus and were discovered by Christian de Duve.

The anode is the electrode joined to the positive terminal of the supply, so negatively charged ions, the anions, travel to it and give up electrons there; loss of electrons is oxidation.

An emulsion is a colloid in which tiny droplets of one liquid are spread through another liquid with which it does not mix.

That Act consolidated several scattered food laws, the most important of them the Prevention of Food Adulteration Act of 1954, into a single statute and created one authority to lay down science-based standards for food, regulate its manufacture, storage, distribution, sale and import, and licence food businesses; its headquarters is…

When an object is weighed under water, the water pushes up on it with a buoyant force, so it seems lighter than in air; this reduced reading is its apparent weight.

A positive power means a converging (convex) lens, and f = 1/P = 1/2 = 0.5 m. The power of a lens is the reciprocal of its focal length in metres: P = 1/f. Its SI unit is the dioptre (D), and 1 D is the power of a lens…

Nylon 6 is made from a single monomer, caprolactam, whose ring opens on heating and joins up into long polyamide chains.

Probiotics are live, helpful microbes taken in food or supplements to improve the balance of bacteria in the gut. The word means "for life", the opposite of antibiotic, "against life".