NSO - Mock Test - 2

The series is as follows:

12 + 1² = 13
13 + 2² = 17
17 + 3² = 26
26 + 4² = 42
42 + 5² = 67

F is the mother of A and E is the husband of F. 'D is the daughter of E' means 'E is the father of D'.
F is the mother of D. D is the sister of A.
From the given information, we cannot get to know the gender of A.
So, A can be the daughter or son of E.

The code is as follows:
R + 1 = S
U - 1 = T
N + 1 = O
In the same way, RIVER will be written as follows:
R + 1 = S
I - 1 = H
V + 1 = W
E - 1 = D
R + 1 = S
Therefore, RIVER is coded as SHWDS.

The relation between the terms is as follows:
D + 5 = I
F + 5 = K
H + 5 = M
In the same way,
M + 5 = R
O + 5 = T
Q + 5 = V
So, MOQ : RTV

In this series, each number is repeated, then 13 is subtracted to arrive at the next number.
Therefore, 27 - 13 = 14

Thermometer is a device which is used to measure temperature. Thermometer is made of a long narrow glass tube. with a bulb at one end. The narrow tube appears as a continuous silver line because it is filled with mercury. Mercury is a metal which is in liquid state at room temperature and it readily expands or contracts at the slightest change in temperature.

When an object repeats its motion after every fixed interval of time, the motion of the object is called periodic motion or oscillatory motion. A pendulum of a clock repeats its motion after every fixed interval of time. So, it is an example of oscillatory motion.

When we pour cold water over a tin can filled with boiled water, the can gets distorted because the air inside the can gets condensed and creates low pressure. The higher pressure from outside distorts the shape of the can.

There are two laws of reflection.
First law: The incident ray, the reflected ray and the normal at the point of incidence lie in the same plane.
Second law: Angle of incidence and angle of reflection are same.

Indicators are substances that detect the acidic or basic nature of a substance by a change in its colour.
Indicators may be natural (obtained from naturally occurring substances) or synthetic ( are synthesized artificially in a laboratory).
Litmus is a natural indicator obtained from lichens.
All the other options are synthetic indicators.

Changes in which the chemical properties of the substance change and a new substance is formed are called chemical changes.
(1), (3) and (4) are all physical changes because there is no formation of any new substance in these processes.
Magnesium ribbon burns in air with a dazzling white light to form magnesium oxide.
Since, a new substance is formed, it is a chemical change.

The department of meteorology is a government department. The meteorological department measures the elements of weather and keeps their record. Meteorologists use data from satellites and analyse the data to forecast about the weather.

Yak wool is obtained from yaks which are found in Tibet and Laddakh.

Earthworms breathe through their skin. The skin of an earthworm always remains moist which helps in breathing.

Platelets are responsible for clotting or coagulation of blood. In case of an injury, the blood clots after some time. This prevents excess loss of blood. Clotting of blood is a defence mechanism in the body.

Collection of rainwater for future use is called rainwater harvesting.
Drip irrigation is a method through which maximum number of plants can be irrigated with a minimum quantity of water. For this, pipelines are laid throughout the rows of plants with holes at strategic points to release water.
In roof irrigation, water is gathered on the roof for irrigation.
All these methods help in saving water, which is an important but scarce resource.

Dark clothes absorb more heat and keep one comfortable in winter. Woollen clothes are used in winter season because wool is a poor conductor of heat. In addition to it, air gets trapped in woollen fibre to further increase the poor conductivity of wool. This prevents the radiation of heat of our body to the surrounding and prevents the cold from surroundings to affect our body.

The S.I. unit of electric current is Ampere.

The centre of the cyclone is called the 'eye'. A cyclone may be 10 km to 15 km high. It is a rotating mass of air. The diameter of the cyclone eye may vary from 10 km to 30 km. The eye of a cyclone is the calm area, but around the eye, air may move with high speeds such as 150 km/h to 250 km/h.

The white light, or visible spectrum, is composed of seven colours. These colours are referred to as VIBGYOR (Violet, Indigo, Blue, Green, Yellow, Orange and Red). When white light passes through a prism, it breaks down into its component colours. This is the reason a rainbow shows all the colours of the visible spectrum.

China rose is a natural indicator that gives a dark pink colour with acids and turns green with bases.

Galvanisation, a the process of coating iron objects with a layer of zinc in order to prevent rusting.
Zinc reacts with the atmospheric oxygen to form a sturdy layer of zinc oxide which protects the metal beneath.

Rainforests are found generally near the equator. Places near the equator receive more sunshine and hence more rainfall. This makes the place hot and humid. Temperatures generally vary from 15^oC to 40^oC near the equator.

There are many animals that bear a thick coat of hair on their bodies. Such animals generally live in cold climates.

Organisms that obtain food from dead and decaying organic matter are called saprophytes. For example: Fungi (moulds, mushrooms and yeasts)

Anaerobic respiration takes place in the absence of oxygen. Anaerobic respiration usually happens in most of the microbes. Alcohol and carbon dioxide are formed at the end of anaerobic respiration. In some cases, lactic acid is formed at the end of anaerobic respiration.

The biological process in which food is utilised to produce energy is called respiration. Respiration is necessary for survival of living beings.

Amphibians, reptiles and mammals use the lungs for breathing. Amphibians breathe through their skin, when they are in water. Smaller animals have different organs for breathing.

The grains of paddy and other cereals is separated from the stalk by threshing.

A kind of plant grown and cultivated on a large scale at a place is called crop. The first step before growing crops is preparation of the soil. For growing a crop, sufficient sunlight, water and nutrients from the soil are essential. Damaged seeds would float on top of the water.

The sewage treatment involves physical, chemical and biological processes to remove impurities from the waste water. Sedimentation and filtration are both physical processes. Aeration is a biological process. Chlorination is a chemical process. Water purified through aeration is not fit for human consumption. It needs to be treated with chlorine. For this, bleaching powder is added to the water. This kills whatever germs may be left in the water and makes it potable.

About 71% of the Earth's surface is covered with water. But out of this, a very small amount is available for human use. Only about 1% of the water is available for human use.

Particles of sandy soil are larger in size. Because of larger size, sand particles cannot fit closely together, and hence, there is enough space among them. So, it is not fit for vegetation because it does not retain water.

Large scale cutting of trees to clear land for human use is called deforestation. Reduced forest cover has led to soil erosion and loss of soil fertility at many places. Reduced forest cover means there is loss of habitat for many animals. Reduced forest cover has disturbed the natural process of recharging of groundwater.

Stethoscope is a device which is used by doctors to listen to the heart beat and pulse. Stethoscope is composed of a long rubber tube, two ear pieces and a diaphragm.

Urine contains 95% water, 2.5% urea and 2.5% other wastes. Urine is excreted from time to time.

Vanilla is used as an olfactory indicator which retains its odour with an acid but loses it with a base.
Red litmus turns blue with bases.
Phenolphthalein is a synthetic indicator which is colourless and remains colourless with acids, but turns pink with bases.
Methyl orange is a synthetic indicator. Synthetic indicators are made in laboratories.