General Science GK Questions with Answers – Page 62

A plane mirror forms an image behind the mirror where light only seems to come from, with left and right swapped.

Electric power equals voltage times current, so the current is 60 W ÷ 240 V = 0.25 A. The relation P = VI comes straight from the definitions: voltage is energy per unit charge and current is charge per second, so their product is energy per second, or power.

Its density is about 0.86 g/cm³, less than that of water, so it floats while it reacts. Potassium is an alkali metal, soft enough to cut with a knife.

Bacteria have peptidoglycan walls and animal cells have no wall, but fungal walls are made of chitin, not cellulose. Statement 1 is correct: peptidoglycan, also called murein, is a mesh of sugars cross-linked by short peptides; penicillin works by blocking its formation.

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.

Two vanadium atoms must balance five oxide ions, each of charge −2, so each vanadium carries +5. In a neutral compound the oxidation states add up to zero.

A liquid boils when its vapour pressure rises to match the pressure of the air above it. As a liquid is heated, more molecules escape as vapour and its vapour pressure climbs.

When light enters a denser medium, its wavelength is divided by the refractive index of that medium. The frequency of light is fixed by its source and does not change on refraction.

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.

Each statement is true: there are plant-eating turtles, fish and marine mammals, and some snakes give birth to live young.

Two liquids that mix completely but boil at clearly different temperatures can be separated by heating the mixture and condensing the vapour of the lower-boiling liquid first.

Adenosine triphosphate stores energy in its phosphate bonds and releases it wherever the cell needs it, so it is called the energy currency of the cell.

This is the order in which these metals stand in the reactivity series, and it matches how vigorously they release hydrogen from dilute hydrochloric acid.

Iron is needed to make haemoglobin, so too little iron means too little haemoglobin and a reduced ability of the blood to carry oxygen.

All three statements correctly describe how particles move in the two kinds of mechanical waves. In a longitudinal wave, such as sound in air, the particles vibrate back and forth along the direction in which the wave travels.

In paper making the raw plant material is cooked with caustic soda, which dissolves the gums, resins and lignin that bind the cellulose fibres together.

Aluminium has three valence electrons, one fewer than silicon, so each aluminium atom leaves a hole that acts as a positive charge carrier.

The air we breathe out carries carbon dioxide, which reacts with limewater to form a white, insoluble solid that makes it look milky.

Acceleration is the change in velocity divided by the time taken, and 10 minutes is one-sixth of an hour.

Without enough vitamin D the body cannot absorb calcium and phosphorus properly, so a child's growing bones stay soft and bend.