Science Outside Delhi Set 2 2023-2024 English Medium Class 10 Question Paper Solution

Consider the following statements about homologous series of carbon compounds:

1. All succeeding members differ by - \[\ce{CH2}\] unit.
2. Melting point and boiling point increases with increasing molecular mass.
3. The difference in molecular masses between two successive members is 16 u.
4. \[\ce{C2H2}\] and \[\ce{C3H4}\] are NOT the successive members of alkyne series.

The correct statements are:

a and b

b and c

a and c

c and d

The number of shells required to write the electronic configuration of Potassium (At. No. 19).

1

2

3

4

Select from the following a process in which a combination reaction is involved:

Black and white photography

Burning of coal

Burning of methane

Digestion of food

The oxide which can react with \[\ce{HCl}\] as well as \[\ce{KOH}\] to give corresponding salt and water is:

\[\ce{CuO}\]

\[\ce{Al2O3}\]

\[\ce{Na2O}\]

\[\ce{K2O}\]

Which of the following is an alloy of copper and tin?

Nichrome

Brass

Constantan

Bronze

Tooth decay begins at the pH of ______.

5.1

5.8

6.5

8.0

Solid calcium oxide reacts vigorously with water to form calcium hydroxide accompanied by the liberation of heat. From the information given above it may be concluded that this reaction ______.

is endothermic and pH of the solution formed is more than 7

is exothermic and pH of the solution formed is 7

is endothermic and pH of the solution formed is 7

is exothermic and pH of the solution formed is more than 7

In human respiratory system, when a person breathes in, the position of ribs and diaphragm will ______.

lifted ribs and curve/dome shaped diaphragm.

lifted ribs and flattened diaphragm.

relaxed ribs and flattened diaphragm.

relaxed ribs and curve/dome shaped diaphragm.

Which of the following endocrine gland does not occur as a pair in the human body?

Adrenal

Pituitary

Testis

Ovary

Which of the following statement(s) is (are) true about human heart?

1. Right atrium receives oxygenated blood from lungs through pulmonary artery.
2. Left atrium transfers oxygenated blood to left ventricle which sends it to various parts of the body.
3. Right atrium receives deoxygenated blood through vena cava from upper and lower body.
4. Left atrium transfers oxygenated blood to aorta which sends it to different parts of the body.

a

b and d

a and d

b and d

Which one of the. following organism is represented by this diagram?

Spirogyra

Planaria

Yeast

Rhizopus

A cross made between two pea plants produces 50% tall and 50% short pea plants. The gene combination of the parental pea plants must be ______.

Tt and Tt

TT and Tt

Tt and tt

TT and tt

Strength of magnetic field produced by a current carrying solenoid does not depend upon ______.

number of turns in the solenoid

direction of the current flowing through it

radius of solenoid

material of core of the solenoid

SI unit of electrical resistivity is ______.

ohm per metre³

ohm per metre2

ohm. metre

ohm. metre³

The minimum resistance which can be made using five resistors each of resistance 10 Ω is ______.

`1/50  Omega`

`1/5  Omega`

2 Ω

1 Ω

Consider the following statements in the context of human eye:

1. The diameter of the eye ball is about 2.3 cm.
2. Iris is a dark muscular diaphragm that controls the size of the pupil.
3. Most of the refraction for the light rays entering the eye occurs at the crystalline lens.
4. While focusing on the objects at different distances, the distance between the crystalline lens and the retina is adjusted by ciliary muscles.

The correct statements are:

a and b

a, b and c

b, c and d

a, c and d

Assertion (A): The deflection of a compass needle placed near a current carrying wire decreases when the magnitude of an electric current in the wire is increased.

Reason (R): Strength of the magnetic field at a point due to a current carrying conductor increases on increasing the current in the conductor.

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

Both (A) and (R) are true, but (R) is not the correct explanation of (A).

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

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

Assertion (A): Human female has a perfect pair of sex chromosome.

Reason (R): Sex chromosome contributed by the human male in the zygote decides the sex of a child.

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

Both (A) and (R) are true, but (R) is not the correct explanation of (A).

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

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

Assertion (A): Myopic eye cannot see distant objects distinctly.

Reason (R): For the correction of myopia converging lenses of appropriate power are prescribed by eye surgeons. 

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

Both (A) and (R) are true, but (R) is not the correct explanation of (A).

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

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

Assertion (A): Metals in the middle of activity series are found in nature as sulphides or carbonates.

Reason (R): The sulphide ores are calcinated whereas carbonate ores are roasted to extract metals from them.

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

Both (A) and (R) are true, but (R) is not the correct explanation of (A).

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

Define a decomposition reaction.

Write an equation to show thermal decomposition of ferrous sulphate crystals.

What is meant by a balanced chemical equation?

Why is it necessary for the equation to be balanced?

1. Which one of the two test tubes shows change in colour? Write the changed colour observed in this test tube.
2. What can we conclude from this activity?

Name two types of germ cells present in human beings. List two structural differences between the two.

State the laws of refraction of light.

A ray of light enters from, vacuum to glass of absolute refractive index 1.5. Find the speed of light in glass. The speed of light in vacuum is 3 × 10⁸ m/s.

Use Ohm's law to determine the potential difference across the 3 Ω resistor in the circuit shown in the following diagram when key is closed:

Name the term used for the materials which cannot be broken down by biological processes. Give two ways by which they harm various components of an ecosystem.

Give reasons for the following:

Alveoli in lungs are richly supplied with blood capillaries.

Give reasons for the following:

Respiratory pigment in the blood takes up oxygen and not carbon dioxide.

Give reasons for the following:

During anaerobic respiration, a 3-carbon molecule is formed as an end product instead of CO₂ in human beings.

Name the movements that occur all along the gut in human digestive system. How do they help in digestion?

Where is bile juice stored in human body?

List two roles of bile juice.

In angiosperms why fertilisation cannot take place in flowers if pollination does not take place? Where is zygote located in a flower after fertilisation? What does it develop into?

Write the names of those parts of a flower which serve the same function as the following do in animals:

State any two observations when an electric current is passed through acidulated water, in a container having each electrode covered by test tubes filled with water.

Write the ratio of the mass of the gas collected at the cathode to the mass of the gas collected at the anode.

Draw a labelled diagram to show electrolytic refining of copper. State what happens when electric current is passed through the electrolyte taken in this case.

An object is placed in front of a concave mirror of focal length 12 cm. If distance of the object from the pole of the mirror is 8 cm, then use mirror formula to determine the position of the image formed. Draw a labelled ray diagram to justify your answer in this case.

The image of an object formed by a mirror is real, inverted and is of magnification −1. If the image is at a distance of 30 cm from the mirror, where is the object placed? Give reason to justify your answer.

Where would the image be if the object is moved 15 cm towards the mirror? Draw ray diagram for the new position of the object to justify your answer.

State Fleming's left hand rule. Apply this rule to determine the direction of force experienced by a straight current carrying conductor AB placed in a uniform magnetic field as shown.

What will happen to an electron which enters in the same field in the same direction in which the current is flowing in the conductor AB? Give reason to justify your answer.

Use of pesticides to protect our crops affect organisms at various trophic levels especially human beings. Name the phenomenon involved and explain how does it happen.

Upper half of a convex lens is covered with a black paper. Draw a ray diagram to show the formation of image of an object placed at a distance of 2F from such a lens. Mention the position and nature of the image formed. State the observable difference in the image obtained if the lens is uncovered. Give reason to justify your answer.

An object is placed at a distance of 30 cm from the optical centre of a concave lens of focal length 15 cm. Use lens formula to determine the distance of the image from the optical centre of the lens.

State the reason why carbon can neither form \[\ce{C^4+}\] cations nor \[\ce{C^4−}\] anions but forms covalent compound.

What is meant by homologous series of carbon compounds?

Write the molecular formula of two consecutive members of homologous series of aldehydes. State which part of these compounds determines their

1. physical and 
2. chemical properties

Write the molecular formula and structure of cyclohexane. How many covalent bonds are there in a molecule of cyclohexane?

1. Name a commercially important carbon compound having functional group - OH and write its molecular formula.
2. Write chemical equation to show its reaction with
   1. Sodium metal
   2. Excess conc. sulphuric acid
   3. Ethanoic acid in the presence of an acid catalyst
   4. Acidified potassium dichromate
      Also write the name of the product formed in each case.

Distinguish between hormonal co-ordination in plants and animals.

Which part of the brain is responsible for intelligence?

Which part of the brain is responsible for riding a bicycle?

Which part of the brain is responsible for vomiting?

Which part of the brain is responsible for controlling hunger?

How is human brain protected from mechanical injuries and shocks?

What are tropic movements?

Give an example of a plant hormone which inhibits growth.

Give an example of a plant hormone which promotes cell division.

Explain directional movement of a tendril in pea plant in response to touch. Name the hormone responsible for this movement.

1. List two properties of heating elements.   1
2. List two properties of electric fuse.   1
3. Name the principle on which an electric fuse works. Explain how a fuse wire is capable of saving electrical appliances from getting damaged due to accidently produced high currents.   2
                                      OR
   The power of an electric heater is 1100 W. If the potential difference between the two terminals of the heater is 220 V, find the current flowing in the circuit. What will happen to an electric fuse of rating 5 A connected in this circuit?   2

1. Identify the acid and base from which Sodium chloride is formed.   1
2. Find the cation and the anion present in Calcium sulphate.   1
3. "Sodium chloride and washing soda both belong to the same family of salts." Justify this statement.   2
                                                    OR
   Define the term pH scale. Name the salt obtained by the reaction of Potassium hydroxide and Sulphuric acid and give the pH value of its aqueous solution.   2

1. Which of the cut pieces of the two Planaria could regenerate to form a complete organism?         1
2. Give an example of another organism that follows the same mode of reproduction as Planaria.         1
3. What is the meaning of 'development' in regeneration?         2
                                  OR
   Differentiate between regeneration and fragmentation.         2