General Science Mixed Quiz: Set 121

The heat needed is 50 cal to warm the ice to 0°C, 800 cal to melt it, and 200 cal to warm all 20 g of water to 10°C. Take the specific heat of ice as 0.5 cal/g°C, the latent heat of fusion of ice as 80 cal/g and the…

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 Moon gives out no light of its own; it only reflects sunlight, so it is a non-luminous object. A luminous object produces and emits its own light, while a non-luminous object is seen only because it reflects light falling on it.

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.

Sound travels faster in warmer air, so statement I is wrong, while II and III are right. The speed of sound in a gas is v = √(γP/ρ).

The spring constant is force divided by extension, so its SI unit is newton per metre. Hooke's law says that, within the elastic limit, the restoring force of a spring is proportional to how far it is stretched or compressed: F = −kx.

Using R = L/(σA) with equal lengths, the resistance of Y comes out three times that of X. Resistance falls as conductivity σ and cross-sectional area A rise.

This statement is wrong: soda glass is the soft glass, while pyrex is a hard borosilicate glass. Ordinary soda-lime glass is made from silica (sand), sodium carbonate and limestone; it softens at a fairly low temperature and is used for windows, bottles and tumblers.

An electron's mass is about 1/1836 of a proton's, which is roughly 1/2000. The electron has a mass of about 9.1 × 10⁻³¹ kg, while the proton has about 1.67 × 10⁻²⁷ kg, nearly 1,836 times heavier.

The correct answer is B, Bombyx mori, the mulberry silkworm, the only fully domesticated insect of the silk group and the source of most of the world's raw silk.

Paper chromatography separates substances because each one divides, or partitions, itself differently between two liquid phases. In paper chromatography the stationary phase is the water held in the cellulose fibres of the paper, and the mobile phase is the solvent that rises up the paper by capillary action.

This is the incorrect statement, because periodic motion repeats after every interval T, again and again. The time period T of a pendulum is the time for one complete oscillation, that is, the smallest interval after which the bob returns to the same position moving in the same direction.

Graphite has the lowest energy of all forms of carbon at ordinary temperature and pressure, so it is the thermodynamically most stable allotrope.

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.

Chalk, limestone and marble are all forms of calcium carbonate, CaCO₃. Chalk is a soft, porous rock built from the tiny shells of marine plankton.

Gamma rays sit at the far end of the electromagnetic spectrum, with the shortest wavelength and therefore the highest frequency and energy.

Leucoplasts are colourless plastids that store food: starch, oils and proteins. Plastids are found only in plant cells and some algae, and they are of three main kinds.

Lysozyme kills bacteria by breaking down their cell walls, and it is found in saliva, tears and mucus. Lysozyme attacks peptidoglycan, the main material of the bacterial cell wall, by splitting the bonds between its sugar units; the weakened cell then bursts.

Urine is made in the kidneys, carried down by the ureters, stored in the bladder and passed out through the urethra.

A nerve impulse is carried by the movement of sodium ions into the nerve cell and potassium ions out of it.