General Science GK Questions with Answers – Page 13

In simple harmonic motion the velocity is given by omega times the square root of A squared minus x squared.

The English engineer Thomas Savery patented a steam pump in 1698 and called it the Miner's Friend, as it was meant to pump water out of flooded mines.

Each half of the wire has a resistance of 10 Ω, and two 10 Ω resistors in parallel give 5 Ω. The resistance of a wire is R = ρL/A, so it is directly proportional to its length when the material and thickness stay the same.

In myopia, or short-sightedness, a person sees near objects clearly but distant objects look blurred because their image forms in front of the retina.

Two miscible liquids that form a homogeneous mixture are separated by distillation, which uses the difference in their boiling points.

The urinary bladder is a hollow muscular sac made of smooth muscle and a stretchable lining; it has no cartilage.

An electric generator converts mechanical energy into electrical energy and so produces electric current. A generator works on electromagnetic induction, discovered by Michael Faraday in 1831.

For lenses in contact the powers simply add, and here they are +2 D and +4 D. The power of a lens is the reciprocal of its focal length in metres, P = 1/f, and its unit is the dioptre.

Soap micelles are large enough to scatter the light passing through the solution, and this scattering makes soapy water look cloudy.

Lactose, the sugar of milk, is a disaccharide formed when one molecule of glucose joins one molecule of galactose. Disaccharides are sugars made of two simple sugar units, or monosaccharides, linked by a glycosidic bond.

Total internal reflection happens only when light inside a denser medium meets the boundary with a rarer one at an angle larger than the critical angle, and all of the light is reflected back.

In graphite each carbon atom is joined to three others in a flat layer of hexagonal rings, like a honeycomb.

Covaxin is an inactivated virus vaccine and Sputnik V is a viral vector vaccine, but Covishield is a viral vector vaccine, not an mRNA vaccine.

Sponges are the members of phylum Porifera, a name that means "pore bearers", because their bodies are full of tiny pores called ostia.

Sclerenchyma cells are dead at maturity, with thick walls hardened by lignin. Sclerenchyma is the tissue that makes plants hard and stiff.

For a straight wire, the right-hand thumb rule links the current to the circular field lines around it. Hold the wire in the right hand with the thumb along the current; the curled fingers then show the direction of the magnetic field lines, which form concentric circles around the wire.

Sound needs a material medium to travel, and in air its particles vibrate back and forth along the direction the wave moves.

In a metal, the outer electrons of the atoms are not tied to any one atom and drift through the lattice when a voltage is applied, carrying the current.

A compound microscope magnifies more when both its lenses have short focal lengths. In a compound microscope the objective forms a real, enlarged image, and the eyepiece magnifies it further like a simple magnifier.

Cinnabar is mercury sulphide, HgS, the chief ore from which mercury is obtained. Cinnabar is a bright red mineral.