Science Outside Delhi set 2 2019-2020 English Medium Class 10 Question Paper Solution

How are covalent bonds formed?

Define electropositivity.

The atomic radii of first group elements are given below:

State the reason behind the observed trend in the above elements.

Answer question numbers (a) to (d) on the basis of your understanding of the following paragraph and the related studies concepts.

1. How is hydropower harnessed?  1
2. Define 1 MW.  1
3. Mention two disadvantages of constructing Tehri Dam. 1
4. What happens when water from great heights is made to fall on blades of turbine?  1

Questions numbers (a) to (d) are based on table given below. Study the table in which the levels of Thyroid Stimulating Hormone (TSH) in women are given and answer the questions that follow on the basis of understanding of the following paragraph and the related studied concepts.

Women are at greater risk for developing abnormal TSH levels during menstruation. while giving birth and after going through menopause. Around 6% of women in the United States have some kind of thyroid problem compared to 3% of men. Despite claims that high TSH increases your risk for heart disease, a 2013 study found no link between high TSH and heart diseases. But a 2017 study showed that older women are especially at risk for developing thyroid cancer if they have high levels along with thyroid nodules.

1. A 35 year old woman has TSH level 6.03 mU/L. What change should she bring in her diet to control this level?  1
2. When do women face a greater risk of abnormal TSH level?  1
3. State the consequence of low TSH level.  1
4. Name the mineral that is responsible for synthesis of hormone secreted by thyroid gland.  1

The sky appears dark to passengers flying at very high altitudes mainly because:

Scattering of light is not enough at such heights.

There is no atmosphere at great heights.

The size of molecules is smaller than the wavelength of visible light.

The light gets scattered towards the earth.

A cylindrical conductor of length l and uniform area of cross section A has resistance R. Another conductor of length 2l and resistance R of the same material has area of cross section. 

`"A"/2`

`(3"A")/2 `

2A 

3A 

The maximum resistance which can be made using four resistor each of resistance `1/2` Ω is ______.

2 Ω

1 Ω 

2.5 Ω

8 Ω

A diagram of traditional water harvesting system is given below:

The statement, which defines the system and its parts is

This is an ideal setting of the Khadin system and A = Catchment area; B = Saline area & C = Shallow dugwell

This is an ideal setting of the Shallow dugwell system and A = Catchment area; B = Saline area and C = Khadin

This is an ideal setting of Catchement area and A = Khadin, B = Saline area and C = Shallow dugwell

This is showing Saline area and A = Cate ment area; B = Khadin and C = Shallow dugwell

The major ill effect of monoculture practice in forests is on the ______.

biodiversity which faces large destruction.

local people whose basic needs can no longer be met from such forests.

industries

forest department

Several factories were pouring their wastes in rivers A and B. Water samples were collected from these two rivers. It was observed that sample collected from river A was acidic while that of river B was basic. The factories located near A and B are:

Soaps and detergents factories near A and alcohol distillery near B.

Soaps and detergents factories near B and alcohol distillery near A.

Lead storage battery manufacturing factories near A and soaps and detergents factories near B.

Lead storage battery manufacturing factories near B and soaps and detergents factories near A.

In which of the following, the identity of initial substance remains unchanged?

Curdling of milk

Formation of crystals by process of crystallisation

Fermentation of grapes

Digestion of food

An aqueous solution ‘A’ turns the phenolphthalein solution pink. On addition of an aqueous solution ‘B’ to ‘A’, the pink colour disappears. Which of the following statement is true for the solutions ‘A’ and ‘B’.

A is strongly basic and B is a weak base.

A is strongly acidic and B is a weak acid.

A has a pH greater than 7 and B has a pH less than 7.

A has a pH less than 7 and B has a pH greater than 7.

An element ‘X’ is forming an acidic oxide. Its position in modern periodic table will be:

Group 1 and Period 3

Group 2 and Period 3

Group 13 and Period 3

Group 16 and Period 3

Consider the following statements about an element ‘X’ with number of protons 13.

1. It forms amphoteric oxide
2. Its valency is three
3. The formula of its chloride is XCl₃

The correct statements(s) is/are:

only (A)

only (B)

(A) and (C)

(A), (B) and (C)

Assertion (A): Following are the members of a homologous series:

CH₃OH, CH₃CH₂OH, CH₃CH₂CH₂OH

Reason (R): A series of compounds with same functional group but differing by - CH₂ - unit is called a homologous series.

Both (A) and (R) are true and (R) is correct explanation of the assertion.

Both (A) and (R) are true and (R) is correct explanation of the assertion.

(A) is true but (R) is false.

(A) is false but (R) is true.

Assertion (A): Alloys are commonly used in electrical heating devices like electric iron and heater.

Reason (R): Resistivity of an alloy is generally higher than that of its constituent metals but the alloys have low melting points then their constituent metals.

Both (A) and (R) are true and (R) is correct explanation of the assertion.

Both (A) and (R) are true and (R) is correct explanation of the assertion.

(A) is true but (R) is false.

(A) is false but (R) is true.

State the change in colour observed in following case mentioning the reason:

Silver chloride is exposed to sunlight.

Mention with reason the colour changes observed when:

copper powder is strongly heated in the presence of oxygen.

Mention with reason the colour changes observed when:

a piece of zinc is dropped in copper sulphate solution.

Complete and balance the following chemical equation: 

\[\ce{NaOH_{(aq)} + Zn_{(s)} ->}\]

Complete and balance the following chemical equation:

CaCO₃(s) + H₂O(l) + CO(g) →

Complete and balance the following chemical equation:

HCl_(aq) + H₂O_(l) → 

During electrolysis of brine, a gas G is liberated at anode When this gas ‘G’ is passed through slaked lime, a compound ‘C’ is formed, which is used for disinfecting drinking water.

1. Write formula of ‘G’ and ‘C’.
2. State the chemical equation involved.
3. What is common name of compound ‘C’? Give its chemical name.

Three elements X, Y and Z have atomic numbers 7, 8 and 9 respectively.

1. Arrange them in the decreasing order of their atomic radii.
2. Which of the three is most electronegative? Why?
3. Write the formula of compound formed between
   1. X and Y
   2. X and Z

From the following groups of organisms create a food chain which is the most advantageous for Human being in terms of energy.

State the possible disadvantage if the cereal plant is growing in soil rich in pesticides.

Construct a food web using the organisms mentioned above.

Write two harmful effects of using plastic bags on the environment. Suggest alternatives to the usage of plastic bags.

List any two practices that can be followed to dispose off the waste produced in our homes.

Define ecosystem.

Autotrophs are at the first level of food chain. Give reason.

In a food chain of frog, grass, insect and snake, assign trophic level to frog.

1. Explain the role of UV radiation in producing ozone layer.
2. Mention the reaction involved.

Why is excessive use of CFCs a cause of concern?

List four factors that could lead to speciation. Which of them cannot be a major factor in the speciation of a self-pollinating plant species?. Give reason to justify your answer.

A green stemmed rose plant denoted by GG and a brown stemmed rose plant denoted by gg are allowed to undergo a cross with each other.

1. List your observations regarding:
   1. Colour of stem in their F₁ progeny
   2. Percentage of brown stemmed plants in F₂ progeny if F₁ plants are self pollinated.
   3. Ratio of GG and Gg in the F₂ progeny.
2. Based on the finding of this cross, what conclusion can be drawn?

Water has refractive index 1.33 and alcohol has refractive index 1.36. Which of the two medium is optically denser? Give reason for your answer.

Draw a ray diagram to show the path of a ray of light passing obliquely from water to alcohol.

State the relationship between angle of incidence and angle of refraction in the above case.

Give reasons for the following:

There is either a convergence or a divergence of magnetic field lines near the ends of a current carrying straight solenoid.

Give reasons for the following:

The current carrying solenoid when suspended freely rest along a particular direction.

Give reasons for the following:

The burnt out fuse should be replaced by another fuse of identical rating.

1. With the help of a labelled ray diagram show the path followed by a narrow beam of monochromatic light when it passes through a glass prism.
2. What would happen if this beam is replaced by a narrow beam of white light?

A person is suffering from both myopia and hypermetropia.

1. What kind of lenses can correct this defect?
2. How are these lenses prepared?

A person needs a lens of power +3D for correcting his near vision and –3D for correcting his distant vision. Calculate the focal lengths of the lenses required to correct these defects.

Write balanced chemical equation to explain what happens, when Mercuric oxide is heated.

Write balanced chemical equation to explain what happens when a mixture of cuprous oxide and cuprous sulphide is heated.

Write balanced chemical equation to explain what happens, when Aluminium is reacted with manganese dioxide.

Write balanced chemical equation to explain what happens, when ferric oxide is reduced with aluminium.

Write balanced chemical equation to explain what happens, when zinc carbonate undergoes calcination.

By the transfer of electrons, illustrate the formation of bond in magnesium chloride and identify the ions present in this compound.

Ionic compounds are solids. Give reasons.

With the help of a labelled diagram show the experimental set up of action of steam on a metal.

Carry out following conversion:

Ethanol to ethane

Carry out following conversion:

Ethanol to Ethanoic acid

Differentiate between addition reaction and substitution reaction. Give one example of each.

How do leaves of plants help in excretion?

Describe the structure of nephrons.

Describe the function of a nephron.

Draw a diagram showing germination of pollen on stigma of a flower and mark on it the following organs/parts:

1. Pollen grain
2. Pollen tube
3. Stigma
4. Female germ cell

State the significance of pollen tube.

Name the parts of flower that develop after fertilization into:

1. Seed
2. Fruit

“Use of a condom is beneficial for both the sexes involved in a sexual act,” Justify this statement giving two reasons.

How do oral contraceptive help in avoiding pregnancies?

What is sex selective abortion?

How does sex selective abortion affect a healthy society? (State any one consequence)

Define power.

A torch bulb is rated 5 V and 500 mA. Calculate Its

1. Power
2. Resistances
3. Energy consumed when it is lighted for 2½ hours.

A security mirror used in a big showroom has radius of curvature 5 m. If a customer is standing at a distance of 20 m from the cash counter, find the position, nature and size of the image formed in the security mirror.

Neha visited a dentist in his clinic. She observed that the dentist was holding an instrument fitted with a mirror. State the nature of this mirror and reason for its use in the instrument used by dentist.

Rishi went to a palmist to show his palm. The palmist used a special lens for this purpose.

1. State the nature of the lens and reason for its use.
2. Where should the palmist place/hold the lens so as to have a real and magnified image of an object?
3. If the focal length of this lens is 10 cm and the lens is hold at a distance of 5 cm from the palm, use lens formula to find the position and size of the image.