General Science Mixed Quiz: Set 119

With the velocity changing steadily from 5 m/s to 7 m/s, the average velocity is 6 m/s, and 6 m/s × 3 s = 18 m. For uniform acceleration, displacement s = ((u + v)/2) × t. Here u = 5 m/s, v = 7 m/s and t = 3…

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 work done against gravity is mgh = 50 × 10 × 8 = 4,000 J, and doing it in 10 s needs 4,000 ÷ 10 = 400 W. Power is the rate of doing work, P = W/t, and its SI unit is the watt (1 W = 1…

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.

Newton's law of gravitation is an independent law of nature; it cannot be derived from his three laws of motion.

The Swedish naturalist Carl von Linne, known in Latin as Carolus Linnaeus, arranged plants and animals in a hierarchy of ranks and gave biology the two-word system of scientific names in his works Systema Naturae and Species Plantarum, so he is called the father of taxonomy.

The heat given out by 2 g of steam equals the heat taken in by 250 g of water, and that balance gives L = 550 Cal/g. The water warms from 20°C to 25°C, so it absorbs 250 × 1 × 5 = 1250 Cal.

Golden Rice carries genes that let the grain make beta carotene, the orange pigment that the human body converts into vitamin A, and the colour of the grain gives the variety its name; the aim is to reduce night blindness and childhood blindness in populations whose diet is mainly rice.

Light from the bottom bends as it passes from water into air, so the bottom seems nearer than it really is.

Capra hircus is the scientific name of the domestic goat, in which Capra is the genus and hircus the species, written in the two-word form that Carl Linnaeus gave to biology.

SONAR uses sound waves under water to find the distance and direction of objects. A SONAR set on a ship has a transmitter that sends out pulses of ultrasound and a detector that picks up their echo from the sea bed, a shoal of fish, a wreck or a submarine.

Pliers and scissors are each made of two arms joined at one rivet, and each arm is a complete class 1 lever, so the tool is called a double lever.

Resistance varies inversely with the area of cross-section, and doubling the diameter makes the area four times larger. The resistance of a wire is R = ρl/A, where ρ is the resistivity of the metal, l the length and A the cross-sectional area.

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.

Rutherford's gold foil experiment showed that an atom's positive charge and almost all its mass sit in a tiny central nucleus.

The receptors that pick up taste are called gustatory receptors, and they sit inside the taste buds on the tongue.

Platinum only gets hot and may glow; it does not react, and on cooling the crucible is exactly as it was, so the change is physical.

Copper with dilute nitric acid gives copper nitrate, water and nitric oxide: 3Cu + 8HNO 3 → 3Cu(NO 3 ) 2 + 2NO + 4H 2 O. Nitric acid is a strong oxidising agent, so metals usually do not release hydrogen from it; instead the acid itself is reduced, and…

Silver turns black in air because it reacts with sulphur compounds, mainly hydrogen sulphide, to form a thin black coating of silver sulphide (Ag₂S).

In a micelle it is the long hydrocarbon tail that points into the oil droplet, while the ionic end faces outward into the water, so statement D reverses the real picture.