Science Outside Delhi set 3 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.

Identify the type of the following reaction. Also write a balanced chemical equation for the reaction.

A reaction in which the reaction mixture becomes warm.

Identify the type of the following reaction. Also write a balanced chemical equation for the reaction.

A reaction in which an insoluble substance is formed.

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.

Study the data of the following three categories A. B and C.

1. From the given three categories A, B and C, pick the one which forms Dobereiner’s Triads.
2. Why did Mendeleev placed elements of category A, B and C in three different groups?
3. Is Newland law of octaves applicable to all the three categories?

Give reason to justify your answer.

State with reason the consequence of decrease in number of carnivores in an ecosystem.

In a food chain, state the trophic level at which the concentration of harmful chemicals is maximum. Why is it so?

How is ozone layer formed? 

State the importance of ozone to all life forms on Earth.

Why was there a sharp in the amount of ozone in the atmosphere in 1980’s.

State the role played by the following in the process of digestion:

Enzyme trypsin

State the role played by the following in the process of digestion:

Enzyme lipase

List two functions of finger like projections present in the small intestine.

Classify the following as homologous or analogous pairs:

1. Broccoli and Cabbage
2. Ginger and Raddish
3. Fore limbs of birds and lizard
4. Wings of a bat and Wings of a bird

State the main feature that categorises a given pair of organs as homologous or analogous.

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?

State the Snell’s laws of refraction of light.