NSO - Mock Test - 3

A horse lives in a stable.
Rabbits live in burrows.
So here, the horse is to stable as rabbit is to burrows.

The correct order is:
Room House Street Town District
3 1 2 4 5

The pattern is + 2, + 4, + 2, + 4, ..... So, the missing term = 25 + 4 = 29.

The metallic plate feels colder as compared to the wooden plate because the metallic plate is a good conductor of heat. When you touch steel, your skin is at body temperature while the steel is at room temperature, about 70 degrees Fahrenheit. Heat flows quickly from the warm skin to the highly conductive steel. Your skin rapidly cools off and feels cold. When you touch wood, it doesn't conduct heat very well and blocks the flow. Your skin doesn't cool off, and hence, doesn't feel cold.

Both the rooms have the same temperature because when we convert 25°C to Fahrenheit, it becomes 77°F. So, option 3 describes the situation correctly.
C / 5 = (F - 32) / 9

25° / 5 = (F - 32°) / 9

5° x 9 = F - 32°

45° + 32° = F

F = 77^o

While running, the hands move in to and fro position, and repeat their motion in a given interval of time. This motion is an oscillatory motion.

The combination of two or more cells is known as a battery.

The device which is used for safety and is based on the heating effect of electric current is the fuse. Its essential component is a metal wire or strip that melts when too much current flows through it, thereby interrupting the current. It is a sacrificial device, and once a fuse has operated, it becomes an open circuit. The fuse must be replaced or rewired, depending on the type.

Air is able to make holes in big banners, meant for promotional purposes, because of its property to exert pressure. Air or wind, blowing at high speeds, exerts pressure on the big banners coming in its way and makes holes in them.

The cyclone is formed by a low pressure system, known as the eye of cyclone, with very high speed winds revolving around it.

All of the above statements are true. The main components presents in carbohydrates are carbon, hydrogen and oxygen. Stomata are the tiny pores present on the surface of leaves, which help in exchange of gases. Algae contain chlorophyll which gives them the green colour.

The dentist uses a concave mirror to see the enlarged image of teeth of patients.

Acids, bases and salts are electrolytes and dissociate into ions in their aqueous solutions and ions are charge carriers. Hence, the solutions of electrolytes conduct electricity.
The passage of electric current through a solution causes chemical reactions to occur.
This is the chemical effect of electric current.
On the passage of electric current through a copper sulphate solution, copper gets deposited on the plate connected to the negative terminal of the battery.

Calamine lotion contains zinc carbonate (ZnCO₃).
When an ant bites, it injects formic acid into the skin, and therefore, basic zinc carbonate is applied to the skin to neutralize the effect of the acid and provide relief.

China rose is a natural indicator which gives dark pink (magenta) colour with acids and turns green with bases.

Acids turn blue litmus paper red. Among the options, HCl is acidic in nature.

NH₃ is ammonia is basic in nature and is used for household cleaning purposes like cleaning the tiles and also removing stubborn stains from the clothes.

Methyl orange is a synthetic indicator that gives pink colour with acids and is yellow with bases.
Litmus is a natural indicator that gives red colour with acids and is blue with bases.
Hence, both C and D can be used to identify acids as well as bases.
However, both phenolphthalein and turmeric do not change colour with acids and hence these indicators are not a suitable choice for testing the acidic nature of vinegar.

Bases can turn the turmeric indicator red, and the only base among the options is option B i.e., NaOH, which is sodium hydroxide.

Galvanisation is the process of depositing a layer of zinc on iron to prevent rusting.
It forms a coating of zinc which, when intact, prevents corrosive substances from reaching the underlying iron.

The process X is digestion of animal waste by the action of anaerobic bacteria for the production of biogas and compost. This is a chemical change.
The process Y is combustion of biogas as a fuel, which is also a chemical change.

An alloys is a homogenous mixture of two or more metals or metals with some non-metal.
Making an alloy is an example of a physical change.

The bodies of penguins are white, and merge into the background. They have a thick layer of skin and move around in groups to keep warm.
Their streamlined bodies and webbed feet make penguins swift swimmers.

In general, meteorologists measure the rainfall by using a "Rain gauge", also called 'Ombrometer' or 'Puliometer', expressed in centimetres or millimetres. So, the device used by Jack is Ombrometer.

The animals living in the tropical rainforests show all the adaptations given in the question, because tropical rainforests have extreme conditions, and to survive in those conditions, animals adapt sticky pads, loud voice, bright colours, and strong tails.

Shearing is the first step in processing fibre into wool. It is the removal of the fleece of the sheep along with a thin layer of the skin.
The second step would be scouring, which is the process of washing the sheared hair. The woollen fibres are thoroughly washed in big tanks to remove grease, dust and dirt by fully mechanised machines.
The third step is sorting, which is done after scouring to separate hair of different textures and types. This is to separate the low and good quality fibres.
The fourth step is dyeing i.e., picking out of any remaining burrs (small fluffy fibres) is followed by the dyeing of fibres in various colours.
The final steps are straightening, combing and rolling. Once the dyeing process is complete, the fibres are straightened, combed and rolled into yarn.

The process of rearing silkworms to obtain silk from them is known as Sericulture. Although, there are several commercial species of silkworms. Bombyx mori (the caterpillar of the domesticated silk moth) is the most widely used and intensively studied silkworm.

An organism that feeds on or derives nourishment from decaying organic matter is known as saprotroph, and its example is fungus

An organism living in symbiosis with another is known as a symbiont.

This mode of nutrition, in which organisms take in nutrients in solution form from dead and decaying matter, is called saprotrophic nutrition. Plants which use saprotrophic mode of nutrition are called saprotrophs.

The movement shown by a plant in response to water is called hydrotropism.
Hydrotropism (hydro - "water"; tropism - "involuntary orientation by an organism, that involves turning or curving as a positive or negative response to a stimulus") is a plant's growth response in which the direction of growth is determined by a stimulus or gradient in water concentration.

Cytokinins (CK) are a class of plant growth substances (phytohormones) that promote cell division, or cytokinesis, in plant roots and shoots. They are involved primarily in cell growth and differentiation, but also affect apical dominance, axillary bud growth, and leaf senescence.

All the three factors i.e., temperature, light intensity and oxygen affect photosynthesis.
Photosynthesis is the process by which green plants and some other organisms use sunlight to synthesise nutrients from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a by-product.

Plastids are present in plant cell, but absent in animal cell.
The plastid is a major double-membrane organelle found, among others, in the cells of plants and algae. Plastids are the site of manufacture and storage of important chemical compounds used by the cell.

Plants need to excrete excess carbon dioxide and oxygen. Carbon dioxide is a waste product of aerobic respiration in plant cells. Oxygen is a waste product of photosynthesis.

The process to move sugar in plants through phloem is called 'translocation'.
Translocation is the movement of materials from leaves to other tissues throughout the plant. Plants produce carbohydrates (sugars) in their leaves by photosynthesis, but non-photosynthetic parts of the plant also require carbohydrates and other organic and non-organic materials. Phloem moves sugars from the places they are made (the leaves) to various non-photosynthetic parts of the plant.

Biomes are very large ecological areas on earth's surface, with fauna and flora (animals and plants) adapting to their environments. Biomes are often defined by abiotic factors such as climate, relief, geology, soils and vegetation.

IN STEM: Various factors are at play during transportation of water through xylem in stems. The transport of water through xylem is also called 'Ascent of Sap'.

a. Root pressure is responsible for the rise of water to some height.
b. Capillary action pushes the water further up. The rise of liquid in a very narrow tube is called capillary action. Capillary action happens because of very small diameter of the tube.
c. Adhesion Cohesion: Water molecules stick to each other and make a continuous column inside the xylem tubes.
d. Transpiration pull: There are numerous small pores on the surface of leaves. These pores are called stomata. Water vapour is continuously removed through stomata during daytime. Removal of water vapour in plants is called transpiration. This creates a pull in the underlying xylem tissues. The pull is called transpiration pull. Transpiration pull creates a suction effect on the water column inside the xylem.

Image is formed by intersection of reflected rays, and it can be straight or inverted.
Shadow does not provide information such as colour, structure etc., and it is never inverted.

1. The zygote develops into an embryo. - True
2. Stigma contains pollen grains which produce male gametes. - False (Instead of stigma, it should be anther)
3. The cell which results after fusion of gametes is called a zygote. - True