NSO - Mock Test - 3

The given codes are according to the number of letters. The word 'football' has 8 letters and 'hockey' has 6 letters. In the same manner, 'badminton' will have 9 as its code.

Two alternate series are going as follows:
54, 15, 24, 16
16 × 1.5 = 24
24 × 1.5 = 36
36 × 1.5 = 54
The second series is 9, 6, 4
4 × 1.5 = 6
6 × 1.5 = 9
So, 15 is the wrong number.

Since Amit has no brother, his father's son is he himself.
So, the man who is talking is the father of the man in the photograph.
The man in the photograph is his son.

(3)³ - 1 = 26
(4)³ - 1 = 63

Similarly,
(8)³ - 1 = 511
(9)³ - 1 = 728

25 × 25 = 625 - 25 = 600
26 × 26 = 676 - 26 = 650
27 × 27 = 729 - 27 = 702
28 × 28 = 784 - 28 = 756
29 × 29 = 841 - 29 = 812

When the charge particle is moving parallel to the magnetic field, force exerted by the magnetic field on it will be zero. The force exerted by the electric field on the electron will be opposite to the direction of the electric field.

Hence, if the electron is moving parallel to the electric field and the magnetic field, the electron will move in the same straight direction with decreasing speed.

All sour substances like curds and pickles contain acids, and acids react with metals.
Such food if kept in brass or copper vessels will cause chemical reactions, which are likely to yield toxic products.

Magnesium is a reactive metal and it reacts with the atmospheric oxygen to form a layer of magnesium oxide on its surface.
This oxide of magnesium further reacts with the CO₂ and water vapour in the air to form a layer of basic magnesium [MgCO₃.Mg(OH)₂].
In order to remove this layer, the magnesium ribbon is cleaned with sand paper.

This is a double replacement reaction in which an exchange of ions takes place between the reactant species.
BaCl₂(aq) + Na₂SO₄(aq) → BaSO₄(s) + 2NaCl(aq)
The BaSO₄ formed is an insoluble salt and appears as a white ppt.

When an iron nail is dipped in the copper sulphate solution, the iron displaces copper from the copper sulphate because iron is more reactive than copper. Therefore, the colour of the solution changes from the blue of copper sulphate to the green of ferrous sulphate.

The main limitation of the Dobereiner's classification was that all the known elements could not be classified into triads on the basis of their properties.
Only three triads were identified:

1. Triad of alkali metals
2. Triad of alkaline earth metals
3. Triad of halogens.

In the modern periodic table, atoms with similar electronic configuration are placed in the same vertical column or group and they exhibit similarity in their chemical properties. Hence, option (2) is correct.
In a group, the number of valence electrons remains the same.
Elements across a period show an increase in the number of valence electrons.

A balanced equation should have equal number of atoms of each element on each side of the equation.
All the elements besides Fe are already balanced.
The balanced equation shows that 3 moles of Fe react with 4 moles of H₂O to produce 1 mole of Fe₃O₄ and 4 moles of H₂.

A double displacement reaction is the one in which an exchange of ions takes place between the reactant species.
Option I depicts a double displacement reaction.
2KBr (aq) + Bal₂ (aq) → 2KI (aq) + BaBr₂ (aq)
Option II depicts a displacement reaction in which a more reactive halogen displaces a less reactive one.

Gibberellins were discovered in 1926 by a Japanese scientist, Eiichi Kurosawa, studying bakanae, the "foolish seedling" disease in rice. It was first isolated in 1935 by Teijiro Yabuta and Sumuki, from fungal strain (Gibberella fujikuroi) provided by Kurosawa.

Ciliated epithelial tissue is found in our respiratory tract and in the Fallopian tubes of women. Ciliated epithelium contains goblet cells, which secrete mucous. This mucous, combined with the cilia on the tissue, helps move harmful particles out of our bodies to keep us healthy.

The primary role of hydrochloric acid is to sterilise the food you eat and to prevent harmful bacteria from entering the GI tract. HCl also triggers the release of enzymes such as pepsin, which are essential for the digestion of protein.

Villi are adapted for the maximum absorption of digested food molecules. This is because the folded villi greatly increase the surface area of the intestine; the villi are made of a single layer of thin cells; beneath the villi is an extensive blood capillary network to distribute the absorbed food molecules.

Capillaries are the smallest of the body's blood vessels. They are only one cell thick, and they are the site of the transfer of oxygen and other nutrients from the bloodstream to other tissues in the body. They also collect carbon dioxide waste materials and fluids for return to the veins.

All sponges possess a remarkable ability to regenerate lost parts. A piece cut from the body of a sponge is capable of growing into a complete sponge. Due to this, it is impossible to kill a sponge.

A spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. The description given is of fungal spores.

Both the statements are true. Biomagnification is the increasing concentration of a substance, such as a toxic chemical, in the tissues of organisms at successive higher levels in a food chain. Bioaccumulation occurs within a trophic level whereas biomagnification occurs across trophic (food chain) levels.

The hardy lichens are useful bio-indicators for air pollution, especially sulphur dioxide pollution, since they derive their water and essential nutrients mainly from the atmosphere rather than from the soil.

Excess fluoride in water leads to yellowing of teeth. It causes a condition known as dental fluorosis.

The cardiac sphincter, at the upper portion (cardia) of the stomach, prevents the acidic contents of the stomach from moving upward into the esophagus.

The primary form of sugar transported from the site of photosynthesis to the rest of the plant is sucrose. Starch is the storage form of carbohydrates.

Glucose is broken down by the process of glycolysis. This is the common pathway for both aerobic and anaerobic conditions. Under aerobic conditions, pyruvate formed enters the Kreb's cycle. Under anaerobic conditions, pyruvate is converted into lactate in muscles.

Septum is responsible for maintaining rigidity and support to the heart and it helps in proper functioning of the heart.
Inferior vena cava carries de-oxygenated blood from the lower half of the body to the right atrium of the heart. Pulmonary artery is responsible for transporting oxygen-depleted blood away from the heart and towards the lungs.
Left auricle receives blood from the lungs.

Urea is the principal nitrogenous compound which is excreted by the humans. It is synthesised in the liver by urea cycle but excreted via kidneys.