Science Board Sample Paper by shaalaa.com 2023-2024 English Medium Class 10 Question Paper Solution

Identify the product which represents the solid state in the above reaction.

Barium chloride

Barium sulphate

Sodium chloride

Sodium sulphate

The colour of the solution observed after 30 minutes of placing zinc metal in copper sulphate solution is ______.

Blue

Colourless

Dirty green

Reddish Brown

Mild non-corrosive basic salt is ______.

Ca(OH)₂

NaCl

NaOH

NaHCO₃

On adding dilute sulphuric acid to a test tube containing a metal ‘X’, a colourless gas is produced when a burning match stick is brought near it. Which of the following correctly represents the metal ‘X’?

Sodium

Sulphur

Copper

Silver

Which one of the following correctly represents Sodium oxide?

\[\ce{Na^{+2} 2[\overset{××}{\underset{××}{^x_×O^x_×}}]^{\mathbf{−}2}}\]

\[\ce{2Na^{+}[\overset{××}{\underset{××}{^x_×O^x_×}}]^{\mathbf{−}2}}\]

\[\ce{2Na^{+} 2[\overset{××}{\underset{××}{^x_×O^x_×}}]^{\mathbf{−}1}}\]

\[\ce{Na^{+}[\overset{××}{\underset{××}{^x_×O^x_×}}]^{\mathbf{−}2}}\]

An element with atomic number ______ will form a basic oxide.

7 (2, 5)

17 (2, 8, 7)

14 (2, 8, 4)

11 (2, 8, 1)

An element ‘M' has 50% of the electrons filled in the 3^rd shell as in the 2^nd shell. The atomic number of ‘M’ is ______.

10

12

14

18

Generally, food is broken and absorbed within the body of organisms. In which of the following organisms is it done outside the body?

Amoeba

Mushroom

Paramoecium

Lice

Receptors are usually located in sense organs. Gustatory receptors are present in ______.

tongue

nose

eye

ear

A farmer wants to grow banana plants genetically similar enough to the plants already available in his field. Which one of the following methods would you suggest for this purpose?

Regeneration

Budding

Vegetative propagation

Sexual reproduction

The height of a plant is regulated by ______.

DNA is directly influenced by growth hormones.

Genes which regulate the proteins directly.

Growth hormones are under the influence of the enzymes coded by a gene.

Growth hormones are directly under the influence of a gene.

A sportsman, after a long break from his routine exercise, suffered muscular cramps during a heavy exercise session. This happened due to ______.

lack of carbon dioxide and the formation of pyruvate.

presence of oxygen and the formation of ethanol.

lack of oxygen and the formation of lactic acid.

lack of oxygen and the formation of carbon dioxide.

An object is placed in front of a convex mirror. Its image is formed ______.

at a distance equal to the object's distance in front of the mirror.

at twice the distance of the object in front of the mirror.

half the distance of the object in front of the mirror.

behind the mirror and its position varies according to the object's distance.

When light enters the atmosphere it strikes extremely fine particles, which deflect the rays of light in all possible directions, This is due to ______.

reflection of light

atmospheric refraction

scattering of light

dispersion of light

In 1987, an agreement was formulated by the United Nations Environment Programme (UNEP) to freeze the production of “X” to prevent the depletion of “Y”. “X” and “Y” respectively referred to here are ______.

Ozone; CFCs

CFCs; rays UV

CFCs; Ozone

UV rays; Diatomic oxygen

Which of the following features relates to biodegradable substances?

Broken down by biological processes

Remain inert

Persist in the environment for a long time

May harm the ecosystem

• Assertion: Rusting of Iron is endothermic in nature.
• Reason: As the reaction is slow, the release of heat is barely evident.

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

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

A is true but R is false.

A is false but R is true.

• Assertion: The probability of survival of an organism produced through sexual reproduction is more than that of an organism produced through asexual mode.
• Reason: Variations provide advantages to individuals for survival.

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

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

A is true but R is false.

A is false but R is true.

• Assertion: A compass needle is placed near a current-carrying wire. The deflection of the compass needle decreases when the magnitude of the current in the wire is increased.
• Reason: The strength of a magnetic field at a point near the conductor increases by increasing the current.

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

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

A is true but R is false.

A is false but R is true.

• Assertion: Biodegradable substances result in the formation of compost and natural replenishment.
• Reason: It is due to breakdown of complex inorganic substances into simple organic substances.

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

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

A is true but R is false.

A is false but R is true.

Dil. HCl is added to Zn granules. How will you prove that chemical change has taken place here? Support your response with two arguments.

State the post-fertilisation changes that lead to fruit formation in plants.

What is the purpose of making urine in the human body?

Name the organs that store and release the urine.

Why do arteries have thick and elastic walls whereas veins have valves?

The refractive indices of three media are given below:

A ray of light is travelling from A to B and another ray is travelling from B to C.

1. In which of the two cases the refracted ray bends towards the normal?
2. In which case does the speed of light increase in the second medium?

Give reasons for your answer.

A piece of wire of resistance R is cut into three equal parts. These parts are then connected in parallel. If the equivalent resistance of this parallel combination is R₁, what is the value of the ratio R₁ : R?

Refer to the image below and state how the magnetic field pattern indicates regions where the magnetic field is stronger outside the magnet. What happens to the magnetic field when the current in the circuit is reversed?

Study the food chain given below and answer the question that follows:

If the amount of energy available at the third trophic level is 100 joules, then how much energy will be available at the producer level? Justify your answer.

Study the food chain given below and answer the question that follows:

Is it possible to have 2 more trophic levels in this food chain just before the fourth trophic level? Justify your answer.

The given reaction shows one of the processes to extract the metals like Iron and Manganese.

\[\ce{MnO2(s) + Al(s) -> Mn(l) + Al2O3(s) + Heat}\]

Give the reason why the above reaction is known as a thermite reaction.

The given reaction shows one of the processes to extract the metals like Iron and Manganese.

\[\ce{MnO2(s) + Al(s) -> Mn(l) + Al2O3(s) + Heat}\]

Identify the substance oxidised and reduced in the above reaction.

The given reaction shows one of the processes to extract the metals like Iron and Manganese.

\[\ce{MnO2(s) + Al(s) -> Mn(l) + Al2O3(s) + Heat}\]

Give a reason why Aluminium is preferably used in thermite reactions.

An element ‘M’ with electronic configuration 2 8 3 combines separately with Cl^-, `"SO"_4^-2` anions. Write the chemical formulae of the compounds formed. Predict with the suitable reason the nature of the bond formed by element ‘M’ in general. How will the electrical conductivity of the compounds formed vary with respect to ‘M’?

A reddish-brown metal ‘X’, when heated in air, gives a black compound ‘Y’, which when heated in the presence of H₂ gas gives ‘X’ back. ‘X’ is refined by the process of electrolysis; this refined form of ‘X’ is used in electrical wiring. Identify ‘X’ and ‘Y’. Draw a well-labelled diagram to represent the process of refining ‘X’.

We are advised to take iodised salt in our diet by doctors. Justify its importance in our bodies.

What is the probability of a girl or a boy being born into a family? Justify your answer.

1. Explain why the refractive index of any material with respect to air is always greater 1.
2. In the figure below a light ray travels from air into the semi-circular plastic block. Give a reason why the ray does not deviate at the semi-circular boundary of the plastic block.
   
3. Complete the ray diagram of the above scenario when the light ray comes out of the plastic block from the top flat end.

State the law that explains the heating effect of current with respect to the measurable properties in an electrical circuit.

On what factors does the resistance of a conductor depend?

Anannya responded to the question: Why do electrical appliances with metallic bodies are connected to the mains through a three-pin plug, whereas an electric bulb can be connected with a two-pin plug?

She wrote: Three-pin connections reduce heating of connecting wires.

1. Is her answer correct or incorrect? Justify.
2. What is the function of a fuse in a domestic circuit?

Rehmat classified the reaction between Methane and Chlorine in the presence of sunlight as a substitution reaction. Support Rehmat’s view with suitable justification and illustrate the reaction with the help of a balanced chemical equation.

Chlorine gas was prepared using electrolysis of brine solution. Write the chemical equation to represent the change. Identify the other products formed in the process and give one application of each.

Raina while doing certain reactions observed that heating of substance ‘X’ with a vinegar-like smell with a substance ‘Y’ (which is used as an industrial solvent.) in the presence of conc. Sulphuric acid in a water bath gives a sweet-smelling liquid ‘Z’ having molecular formula C₄H₈O₂. When heated with caustic soda (NaOH), ‘Z’ gives back the sodium salt and the compound ‘Y’.

Identify ‘X’, ‘Y’, and ‘Z’. Illustrate the changes with the help of suitable chemical equations.

Given below is a certain situation. Analyze and describe its possible impact on a person:

Testes of a male boy are not able to descend into the scrotum during his embryonic development.

Given below is a certain situation. Analyze and describe its possible impact on a person:

The Vas deferens of a man is plugged.

Given below is a certain situation. Analyze and describe its possible impact on a person:

Prostate and seminal vesicles are not functional.

Given below is a certain situation. Analyze and describe its possible impact on a person:

Egg is not fertilised in a human female.

Given below is a certain situation. Analyze and describe its possible impact on a person:

Placenta does not attach to the uterus optimally.

A doctor has advised Sameer to reduce sugar intake in his diet and do regular exercise after checking his blood test reports. Which disease do you think Sameer is suffering from? Name the hormone responsible for this disease and the organ producing the hormone.

Which hormone is present in the areas of rapid cell division in a plant and which hormone inhibits the growth?

The above image shows a thin lens with a focal length of 5m.

1. What is the kind of lens shown in the above figure?
2. If a real inverted image is to be formed by this lens at a distance of 7m from the optical centre, then show with calculation where should the object be placed.
3. Draw a neatly labelled diagram of the image formation mentioned in (ii).

A 10 cm long pencil is placed 5 cm in front of a concave mirror having a radius of curvature of 40 cm.

1. Determine the position of the image formed by this mirror.
2. What is the size of the image?
3. Draw a ray diagram to show the formation of the image as mentioned in part (i).

The table given below shows the hints given by the quiz master in a quiz.

Based on the above hints answer the following questions.

1. Give the IUPAC names of A and F.
2. Illustrate with the help of chemical equations the changes taking place. (A → C and A → F)

OR

Name the chemical reactions which occur in steps 2 and 5. Identify the compounds formed in these steps if ‘A’ is replaced with its next homologue.

Figures (a) to (d) given below represent the type of ear lobes present in a family consisting of 2 children - Rahul, Nisha and their parents.

Excited by his observation of different types of ear lobes present in his family, Rahul conducted a survey of the type of ear lobes found {Figure (e) and (f)} in his classmates. He found two types of ear lobes in his classmates as per the frequency given below:

On the basis of the above data answer the following questions.

1. Which of the two characteristics - ‘free ear lobe’ or ‘attached ear lobe’ appears to be dominant in this case? Why?
2. Is the inheritance of the free ear lobe linked with the sex of the individual? Give a reason for your answer.
3. What type of ear lobe is present in father, mother, Rahul and his sister Nisha? Write the genetic constitution of each of these family members which explains the inheritance of this character in this family.
   (Gene for the Free ear lobe is represented by F and the gene for the attached ear lobe is represented by f for writing the genetic constitution).
   OR
   Suresh’s parents have attached ear lobes. What type of ear lobe can be seen in Suresh and his sister Siya? Explain by giving the genetic composition of all.

Vinita and Ahmed demonstrated a circuit that operates the two headlights and the two sidelights of a car, in their school exhibition. Based on their demonstrated circuit, answer the following questions.

1. State what happens when switch A is connected to:
   a) Position 2
   b) Position 3
2. Find the potential difference across each lamp when lit.
3. Calculate the current.
   a) in each 12 Ω lamp when lit.
   b) In each 4 Ω lamp when lit.
   OR
4. Show, with calculations, which type of lamp, 4.0 Ω or 12 Ω, has the higher power.