General Science Mixed Quiz: Set 123

A wave moves forward by one wavelength in each cycle, so 150 wavelengths take 150 cycles, and 150 cycles at 300 per second take half a second.

The 2011 FSSAI labelling rules made the list of ingredients, nutrition information and the vegetarian or non-vegetarian mark compulsory, but not medical advice on allergies.

The N shell is the fourth shell (n = 4), and a shell can hold at most 2n² electrons, which gives 2 × 16 = 32.

Meiosis halves them in the gametes, and fertilisation restores them in the offspring. Each parent makes gametes by meiosis, so a human egg or sperm carries 23 chromosomes instead of 46.

Vinegar is a dilute solution of ethanoic acid, commonly called acetic acid, in water. Vinegar contains about 5 to 8 per cent ethanoic acid (CH 3 COOH) and is made by the fermentation of sugar or alcohol by acetic acid bacteria.

The body makes nitric oxide (NO) itself, and it relaxes the walls of blood vessels so that they widen and carry more blood.

Prokaryotic cells such as bacteria have no membrane-bound organelles, so they lack mitochondria. Prokaryotes have no true nucleus: their DNA lies in a region called the nucleoid, and they have no mitochondria, chloroplasts, endoplasmic reticulum or Golgi body.

Pinctada margaritifera is the black lip pearl oyster, a bivalve mollusc of the warm shallow water of the Indo-Pacific, where it fastens itself to coral reefs by strong threads.

These are the three main divisions of the human brain. The fore brain is the largest part.

The velocity ratio of a pulley system is the distance moved by the effort divided by the distance moved by the load, so it is 12 divided by 3, that is 4.

TB spreads through the air when an infected person coughs, sneezes or speaks and others breathe in the tiny droplets carrying the bacteria.

Temporary hardness comes from dissolved calcium and magnesium hydrogencarbonates (bicarbonates), and it can be removed simply by boiling. On boiling, calcium hydrogencarbonate breaks down into insoluble calcium carbonate, water and carbon dioxide, and the carbonate settles out; this is the scale seen inside kettles.

Only statement III is wrong, because colloidal particles are too small to be seen with the naked eye. Mixtures are graded by particle size.

Balance is controlled by the inner ear, which holds the vestibular apparatus alongside the organ of hearing. It is made of three semicircular canals set at right angles to one another and two small sacs, the utricle and the saccule.

For a real object, a concave lens always forms a virtual image, so this statement is wrong. A concave lens is a diverging lens: it spreads out parallel rays so that they seem to come from its focus on the same side as the object.

The working rule for charging a storage battery is that the charging current should be about one-tenth of the ampere-hour capacity of the battery, which is called the C by 10 rate.

Wool is an animal fibre made mainly of the protein keratin. Polymers are giant molecules built from many small repeating units called monomers.

Growth with repair and metabolism are two of the features that mark living beings off from non-living things. A living body grows from inside by making new cells from the food it takes in, and it heals wounds and replaces worn-out tissue.

Jointed legs are the mark of the phylum Arthropoda, to which insects belong; an earthworm has no legs at all.

Each statement says "no virus can", and each is disproved by well-known viruses.