Science Delhi Set 3 2023-2024 English Medium Class 10 Question Paper Solution

Select from the following a decomposition reaction in which source of energy for decomposition is light:

\[\ce{2FeSO4 -> Fe2O3 + SO2 + SO3}\]

\[\ce{2H2O -> 2H2 + O2}\]

\[\ce{2AgBr -> 2Ag + Br2}\]

\[\ce{CaCO3 -> CaO + CO2}\]

When 2 mL of sodium hydroxide solution is added to few pieces of granulated zinc in a test tube and then warmed, the reaction that occurs can be written in the form of a balanced chemical equation as:

\[\ce{NaOH + Zn -> NaZnO2 + H2O}\]

\[\ce{2NaOH + Zn -> Na2ZnO2 + H2}\]

\[\ce{2NaOH + Zn -> NaZnO2 + H2}\]

\[\ce{2NaOH + Zn -> Na2ZnO2 + H2O}\]

\[\ce{MnO2 + 4HCl -> MnCl2 + 2H2O + Cl2}\]

The reaction given above is a redox reaction because in this case ______.

\[\ce{MnO2}\] is oxidised and \[\ce{HCl}\] is reduced.

\[\ce{HCl}\] is oxidised.

\[\ce{MnO2}\] is reduced.

\[\ce{MnO2}\] is reduced and \[\ce{HCl}\] is oxidised.

Consider the following compounds:

\[\ce{FeSO4 ; CuSO4 ; CaSO4; Na2CO3}\]

The compound having maximum number of water of crystallisation in its crystalline form in one molecule is ______.

\[\ce{FeSO4}\]

\[\ce{CuSO4}\]

\[\ce{CaSO4}\]

\[\ce{Na2CO3}\]

In a nerve cell, the site where the electrical impulse is converted into a chemical signal is known as ______.

Axon

Dendrites

Neuromuscular junction

Cell body

A metal and a non-metal that exists in liquid state at the room temperature are respectively:

Bromine and Mercury

Mercury and Iodine

Mercury and Bromine

Iodine and Mercury

At what distance from a convex lens should an object be placed to get an image of the same size as that of the object on a screen?

Beyond twice the focal length of the lens.

At the principal focus of the lens.

At twice the focal length of the lens.

Between the optical centre of the lens and its principal focus.

Carbon compounds:

1. are good conductors of electricity.
2. are bad conductors of electricity.
3. have strong forces of attraction between their molecules.
4. have weak forces of attraction between their molecules.

The correct statements are:

i and ii

ii and iii

ii and iv

i and iii

Oxides of aluminium and zinc are ______.

acidic

basic

amphoteric

neutral

Chromosomes:

1. carry hereditary information from parents to the next generation.
2. are thread like structures located inside the nucleus of an animal cell.
3. always exist in pairs in human reproductive cells.
4. are involved in the process of cell division.

The correct statements are:

i and ii

iii and iv

i, ii and iv

i and iv

1. The sex of a child is determined by what it inherits from the mother.
2. The sex of a child is determined by what it inherits from the father.
3. The probability of having a male child is more than that of a female child.
4. The sex of a child is determined at the time of fertilisation when male and female gametes fuse to form a zygote.

The correct statements are ______.

i and iii

ii and iv

iii and iv

i, iii and iv

Which one of the following organ is NOT a part of human female reproductive system?

Ovary

Uterus

Vas deferens

Fallopian tube

In which of the following organisms, multiple fission is a means of asexual reproduction?

Yeast

Leishmania

Paramoecium

Plasmodium

In bifocal lenses used for the correction of presbyopia ______.

the upper portion is of convex lens for the near vision and lower part is of concave lens for the distant vision.

the upper portion is of convex lens for the distant vision and lower part is of concave lens for the near vision.

the upper portion is of concave lens is for the near vision and lower part is of convex lens for the distant vision.

the upper portion is of concave lens for the distant vision and lower part is of convex lens for the near vision.

The pattern of the magnetic field produced inside a current carrying solenoid is:

Identify the food chain in which the organisms of the second trophic level are missing.

Grass, goat, lion

Zooplankton, phytoplankton, small fish, large fish

Tiger, grass, snake, frog

Grasshopper, grass, snake, frog, eagle

Assertion (A): The rainbow is a natural spectrum of sunlight in the sky.

Reason (R): Rainbow is formed in the sky when the sun is overhead and water droplets are also present in air.

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

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

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

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

Assertion (A): Hydrogen gas is not evolved when zinc reacts with nitric acid.

Reason (R): Nitric acid oxidises the hydrogen gas produced to water and itself gets reduced.

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

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

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

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

Assertion (A): Accumulation of harmful chemicals is maximum in the organisms at the highest trophic level of a food chain.

Reason (R): Harmful chemicals are sprayed on the crops to protect them from diseases and pests.

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

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

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

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

Assertion (A): The rate of breathing in aquatic organisms is much faster than in terrestrial organisms.

Reason (R): The amount of oxygen dissolved in water is very high as compared to the amount of oxygen in air.

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

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

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

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

Write the significance of peripheral nervous system in human beings.

How is human brain protected from mechanical injuries and shocks?

Name one directional growth movement each in response to chemicals and water in plants. Write an example for each of them.

Give reason why herbivorous animals have longer, small intestine than carnivorous animals?

Although 'Pepsin' and "Trypsin' are both protein digesting enzymes yet they differ from each other. Justify this statement by giving one difference between them.

Translate the following statement into a balanced chemical equation. When barium chloride reacts with aluminium sulphate, aluminium chloride and barium sulphate are formed. State the type of this reaction giving reason to justify your answer.

Why don’t two magnetic lines of force intersect each other?

How is a uniform magnetic field in a given region represented ? Draw a diagram in support of your answer.

Draw the pattern of the magnetic field lines due to a straight current carrying conductor indicating the direction of current in the conductor and the direction of the corresponding magnetic field lines.

An object is placed at a distance of 10 cm from a convex mirror of focal length 15 cm. Find the position and nature of the image.

Plants → Deer → Lion

In the given food chain, what will be the impact of removing all the organisms of second trophic level on the first and third trophic level? Will the impact be the same for the organisms of the third trophic level in the above food chain if they were present in a food web? Justify.

A gas 'X' which is a deadly poison is found at the higher levels of atmosphere and performs an essential function.

Name the gas and write the function performed by this gas in the atmosphere. Which chemical is linked to the decrease in the level of this gas? What measures have been taken by an international organisation to check the depletion of the layer containing this gas?

State the rule to determine the direction of a magnetic field produced around a straight conductor-carrying current.

Name and state the rule of determine the direction of force experienced by a current carrying straight conductor placed in a uniform magnetic field which is perpendicular to it. 

Study the diagram given below and answer the questions that follow:

1. Name the defect of vision represented in the diagram. Give reason for your answer.
2. List two causes of this defect.
3. With the help of a diagram show how this defect of vision is corrected.

Define the following:

Reflex action

With the help of a flow chart, show the path of a reflex action such as sneezing.

Which organisms have a three-chambered heart? Why do they have three-chambered hearts?

Give the functions of lymph.

A compound which is prepared from gypsum has the property of hardening when water is mixed in right quantity with it:

1. Write common name and the chemical name of this compound.
2. Give chemical equation for its preparation.
3. List its two uses.

Define a decomposition reaction.

Write chemical equation for the reaction that occurs when lead nitrate is heated strongly in a boiling tube.

In electrolytic decomposition of water two gases are liberated at the electrodes. Give the mass ratio of the gas liberated at the cathode and at the anode.

State whether the currents and potential difference in all the bulbs will be same or different when in a circuit three bulbs of:

1. same wattage are connected in series.
2. same wattage are connected in parallel.
3. different wattage are connected in series.
4. different wattage are connected in parallel.

Two identical resistors of 24 Ω each are connected to a battery of 6 V. Calculate the ratio of the power consumed by the resulting combinations with

1. Minimum resistance
2. Maximum Resistance

Draw a schematic diagram of a circuit consisting of a battery of six 2V cells, a 6 Ω resistor, a 12 Ω resistor, and a 18 Ω resistor and a plug key all connected in series. Calulate the following (when key is closed):

1. Electric current flowing in the circuit.
2. Potential difference across 18 Ω resistor.
3. Electric power consumed in 18 Ω resistor.

Define a homologous series of carbon compounds.

Why is the melting and boiling points of \[\ce{C4H8}\] higher than that of \[\ce{C3H6}\] or \[\ce{C2H4}\]?

Why do we NOT see any gradation in chemical properties of a homologous series compounds?

Write the name and structure of aldehyde with molecular form \[\ce{C3H6O}\].

Write the name and structures of ketone with molecular form \[\ce{C3H6O}\].

Write the name and structure of an organic compound 'X' having two carbon atoms in its molecule and its name is suffixed with '-ol'.

What happens when 'X' is heated with excess concentrated sulphuric acid at 443 K? Write chemical equation for the reaction stating the conditions for the reaction. Also, state the role played by concentrated sulphuric acid in the reaction.

Name and draw the electron dot structure of hydrocarbon produced in the above reaction.

Name three techniques/devices used by human females to avoid pregnancy. Mention the side effects caused by each.

What will happen if in a human female fertilisation takes place?

What will happen if in a human female an egg is not fertilised?

Draw a diagram showing spore formation in Rhizopus and label the (a) reproductive and (b) non-reproductive parts. Why does Rhizopus not multiply on a dry slice of bread?

Name and explain the process by which reproduction takes place in Hydra.

1. When Mendel crossed pea plants with pure tall and pure short characteristics to produce F₁ progeny, which two observations were made by him in F₁ plants?       1
2. Write one difference between dominant and recessive trail.       1
3. 1. In a cross with two pairs of contrasting characters
      

      RRYY	×	rryy
      (Round Yellow)		(Wrinkled Green)

      Mendel observed 4 types of combinations in F₂ generation. By which method did he obtain F₂ generation? Write the ratio of the parental combinations obtained and what conclusions were drawn from this experiment?         2
      OR
   2. Justify the statement:
      "It is possible that a trait is inherited but may not be expressed."         2

Study the data given below showing the focal length of three concave mirrors A, B and C and the respective distances of objects placed in front of the mirrors:

1. In which one of the above cases the mirror will form a diminished image of the object? Justify your answer.     1
2. List two properties of the image formed in case 2.     1
3.   
   1. What is the nature and size of the image formed by mirror C ? Draw ray diagram to justify your answer.     2
      OR
   2. An object is placed at a distance of 18 cm from the pole of a concave mirror of focal length 12 cm. Find the position of the image formed in this case.     2

1. What is the cathode and anode made of in the refining of copper by this process? (1)
2. Name the solution used in the above process and write its formula. (1)
3.    
   1. How copper gets refined when electric current is passed in the electrolytic cell? (2)
      OR
   2. You have two beakers 'A' and 'B' containing copper sulphate solution. What would you observe after about 2 hours if you dip a strip of zinc in beaker 'X and a strip of silver in beaker 'B'? Give reason for your observations in each case. (2)