General Science Mixed Quiz: Set 97

The wave travels at 1,200 m/s, so 2,400 m takes 2 seconds. The speed of any wave is the product of its frequency and wavelength: v = fλ.

The de Broglie wavelength depends only on momentum, so equal wavelengths mean equal momenta. In 1924 Louis de Broglie proposed that every moving particle has a wave linked to it, with wavelength λ = h/p, where h is Planck's constant and p is the linear momentum.

The inner lining of the mouth and the oesophagus is made of squamous epithelium, so an injury to that lining damages this tissue.

Red biotechnology is the branch applied to medicine and health care, including the making of insulin, antibiotics and vaccines. Biotechnology is often divided by colour according to its field of use.

After fertilisation, each ovule grows into a seed, and the ovary that holds the ovules grows into the fruit. In flowering plants, a pollen tube carries two male gametes to the ovule.

A beam seen from the side is visible only because tiny particles send some of its light sideways. Light travelling in a straight line cannot enter our eyes unless something redirects it towards us.

Humans have a single functional insulin gene, INS, on the short arm of chromosome 11, and both chains of insulin come from it.

Rotational kinetic energy is ½Iω², and the ring has the larger moment of inertia. For a thin ring about the axis through its centre and perpendicular to its plane, all the mass sits at distance R, so I = MR².

An anemometer measures how fast the wind is blowing; its name comes from the Greek word anemos, meaning wind.

An ion-exchange resin or zeolite swaps the calcium and magnesium ions that cause permanent hardness for sodium or hydrogen ions.

Milk is a colloid in which tiny droplets of fat are dispersed in water, so it is not uniform at the microscopic level and counts as a heterogeneous mixture.

Jupiter is a planet; it does not make its own light and shines only by reflecting sunlight. A luminous object produces light of its own, as stars do by nuclear fusion in their cores, where hydrogen is turned into helium.

An object denser than the liquid sinks, and one less dense than the liquid floats. By Archimedes' principle, a body placed in a liquid feels an upward buoyant force equal to the weight of the liquid it displaces.

The formula T₀ = 2π√(L/g) holds only for small swings; at large amplitudes the period grows.

Power is the reciprocal of focal length in metres, and 10 cm is 0.1 m, so P = 1 ÷ 0.1 = 10 D. The power of a lens measures how strongly it converges or diverges light.

Anabaena is a cyanobacterium, a prokaryote with no true nucleus, and all prokaryotes are placed in Monera. In R.H.

The Higgs boson found at CERN in 2012 has a mass of about 125 GeV, which among the given options is closest to 100 GeV.

A diode does not obey Ohm's law: the current through it is not proportional to the voltage across it. An ohmic conductor gives a straight-line graph of current against voltage, so its resistance stays constant at a fixed temperature.

Reducing manganese dioxide with aluminium, 3MnO₂ + 4Al → 3Mn + 2Al₂O₃, gives out a large amount of heat. This method of reducing a metal oxide with aluminium powder is called aluminothermy, or the Goldschmidt thermite process.

Biogas is mostly methane, usually about 50 to 75 percent, and it is the methane that burns with a clean blue flame and no smoke.