CBSE(NCERT) GRADE 10 SCIENCE 2023 COMPARTMENT SET4

You want to test for hardness of water but hard water is not available in the laboratory. Which of the following compounds may be dissolved in pure water to make it hard?

Which one of the following properties of Carbon is not responsible for its formation of large number of compounds?

Which of the following will allow the electricity to flow through it/them? (i) Glucose (ii) Dry HCl gas (iii) Alcohol (iv) Dil. H2SO4

Which of the following will allow the electricity to flow through it/them?

In the electrolysis of water, if the mass of the gas collected at the anode is $m_a$ and the mass of the gas collected at the cathode is $m_c$, then the value of $\left(m_c/m_a\right)$ is:

Consider the following substances: (i) Acidified $K_2Cr_2O_7$ (ii) Alkaline $KMnO_4$ (iii) Oxygen (iv) Hydrogen Out of these, the commonly used oxidising agents are:

Select from the following compounds which is not a base:

2 g of yellow sulphur powder is burnt in a china dish and the fumes are collected in a test tube. Water is added in the test tube and the solution is tested separately with blue and red litmus paper. The correct option is:

Which one of the following metals is malleable and a poor conductor of electricity?

The organism in which an outgrowth on the parent body develops into a new individual is :

As compared to daytime, the amount of carbon dioxide released by the plants during night is more because :

The resistance of a wire does not depend on its :

The shape of magnetic field lines produced (i) inside a solenoid (ii) around a straight conductor, both carrying current of the same magnitude are, respectively :

In a cross between pure tall pea plants $(TT)$ and pure dwarf pea plants $(tt)$ the offsprings of $F_1$ generation were all tall. When $F_1$ generation was self-crossed, the gene combinations of the offsprings of $F_2$ generation will be :

How much work is done in moving a charge of $3\ \mathrm{C}$ across two points having a potential difference of $12\ \mathrm{V}$ ?

When an object is placed beyond $2F$ of a convex lens, the nature of the image formed is :

When a narrow beam of white light passes through a glass prism it splits into its component colours? This phenomenon is called :

Assertion (A): After the storm, the sky appears blue. Reason (R): Water droplets act like small prisms and scatter light.

Assertion (A) : A rainbow is an artificial spectrum of white light appearing in the sky after a rain shower. Reason (R) : The water droplets act like small prisms.

Assertion (A): $$Na_2SO_4 + BaCl_2 \rightarrow BaSO_4 + 2NaCl$$ Reason (R): When another solution is added to an aqueous solution, an insoluble substance is formed which is called a precipitate.

Assertion (A) : In the reaction, $\mathrm{Na_2SO_4 + BaCl_2 \rightarrow BaSO_4 + 2NaCl}$, sodium chloride is precipitated. Reason (R) : When an aqueous solution is added to another aqueous solution, an insoluble substance is formed, which is called precipitate.

Assertion (A): Diversity is useful for the survival of a species. Reason (R): Chemical reactions are not completely reliable; therefore in the process of making DNA copies, every time diversity is produced.

Assertion (A) : Variation is useful for the survival of a species over time. Reason (R) : The process of DNA copying will have variation each time because biochemical reactions are not reliable.

Assertion (A): The hormone called auxin promotes growth in plants. Reason (R): It is produced in the apical meristem.

Assertion (A) : A hormone called abscisic acid inhibits growth in plants. Reason (R) : The role of auxins is opposite to that of abscisic acid in plants.

Identify one organ each in human (i) male, and (ii) female reproductive system which plays a role of endocrine gland along with the production of germ cells. Name a hormone secreted by each of them.

(a) State any one advantage of using cloth bags over plastic bags. (b) List any two methods by which the solid wastes generated in urban areas can be safely disposed off.

(a) When a metal reacts vigorously with cold water and the gas evolved on its addition to water starts burning with a pop sound, identify the metal. A metal which does not react with cold or hot water but reacts with steam. A metal which does not react with water of any kind. Identify the metals A, B, C and D.

(b) When two compounds namely sodium chloride and calcium chloride are heated directly, one by one on the flame of a burner, they impart different colours to the flame. (i) Name the colour imparted by (1) sodium chloride and (2) calcium chloride. (ii) Are these compounds soluble in organic solvents such as kerosene or petrol ? Justify your answer.

(a) State Fleming's left-hand rule. (b) An electron enters a magnetic field at right angles to it as shown in the following diagram. Use Fleming's left-hand rule to determine the direction of force experienced by the electron.

(a) Find the magnification of the image formed by a spherical mirror from the following data : $u = 20\text{ cm}, f = 15\text{ cm}.$ OR (b) Draw a labelled ray diagram for the image formation by a concave mirror when an object is placed between its centre of curvature and focus.

(a) Find the magnification of the image formed by a spherical mirror from the following data: u = 20 cm, f = 15 cm.

(b) Draw a labelled ray diagram for the image formation by a concave mirror when an object is placed between its centre of curvature and focus.

Write any two ways by which plants obtain carbon dioxide. What causes the opening and closing of the stomata?

(a) (i) Why are the chemical properties of different members of a homologous series similar? (ii) What is the difference in the number of carbon and hydrogen atoms between any two successive members of a homologous series? Justify your answer by giving an example from (i) alkynes, (ii) alcohols and (iii) aldehydes.

(b) (i) State reasons why (1) Carbon forms strong bonds and stable compounds with most other elements. (2) The melting and boiling points of covalent compounds are low. (ii) Draw the electron dot structure for the molecule of Chlorine (Atomic number 17).

(b) Although the liver does not contain any enzyme yet it plays an important role in digestion. Comment.

(b) With the help of a labelled circuit diagram, illustrate the pattern of the magnetic field lines of the magnetic field produced around a straight current carrying conductor. Explain how, with the help of right-hand thumb rule, we can determine and mark the direction of magnetic field lines due to a current.

A person keeps the reading material much beyond 25 cm from the eye for comfortable reading. Name the defect of vision he is suffering from. How can it be corrected? Draw ray diagrams for (i) the defective eye and (ii) its correction.

What is photosynthesis? Name the organelle and the organs in which photosynthesis takes place. Where does the oxygen

An aqueous solution turns blue litmus red. Which of the following solutions when added in excess would reverse the change?

(a) (i) Aqueous solution of which compound/compounds will turn phenolphthalein solution pink? (1) $\mathrm{CH_3COOH}$ (2) $\mathrm{Ca(OH)_2}$ (3) $\mathrm{HCl}$ (4) $\mathrm{NaOH}$ (ii) Name a gas whose aqueous solution is basic. Write the formula/name of this solution. (iii) A basic substance is used to treat a honey-bee sting. Why? (iv) Name the acid which is present in (1) Tomato and (2) Tamarind.

(a) (i) Name the parts in the human female reproductive system where the following functions take place: (1) Maturation of eggs (2) Fusion of the egg and the sperm (3) Implantation of the zygote (ii) What happens to the egg (1) when it is fertilised? (2) when it is not fertilised?

(b) (i) Explain by giving one example each: (1) Unisexual flowers (2) Bisexual flowers (ii) Name the labelled parts A, B, C and D in the diagram given below. (iii) justify this statement.

(a) You are given three resistors $R_1$, $R_2$ and $R_3$. Write the formula for equivalent resistance when these resistors are connected in (i) series, and (ii) parallel. (b) Three resistors of $2\ \Omega$, $3\ \Omega$ and $4\ \Omega$ are connected in series and this combination is connected to a 9 V battery. An ammeter and a voltmeter are also connected in this circuit. Draw the electric circuit diagram, connecting all the devices in correct order. (i) the current shown by the ammeter and (ii) the potential difference across the $3\ \Omega$ resistor.

(a) You have three resistors $R_1$, $R_2$ and $R_3$. Write the formula for the equivalent resistance of the combination, when these resistors are joined (i) in series and (ii) in parallel. (b) Three resistors of 2, 3 and 4 are connected in series and the combination is connected to a battery of 9 V. An ammeter and a voltmeter are also connected in the circuit. Draw a circuit diagram to show the connection of the above said devices in a correct order. Determine (i) current shown by the ammeter and (ii) potential difference across the 3 resistor.

The iron pillar in Qutab Minar complex in Delhi was built 1600 years ago. It is still standing intact and shows no signs of rusting even today. This shows that the ancient metallurgists of India in those times had fully developed metallurgical processes as well as the techniques of protection of different metals. The protection of metals, was done by several processes like coating of a thin film of another metal, alloying etc. (a) Where is iron placed in the reactivity series of metals? Write the form/forms in which its ores are found in nature. (b) Differentiate between roasting and calcination. (c) Explain any two methods that are employed to prevent rusting/corrosion of metals. OR (c) Why is aluminium used to join railway tracks or the cracked machine parts of iron? Write a balanced chemical equation for the reaction which occurs.

In animals the control and coordination is provided by nervous and muscular tissues. Nervous tissue is made of an organized network of nerve cells or neurons. In human beings, thinking is a complex activity which involves more complex mechanisms and neural connections. These are concentrated in the brain which is the main coordinating centre of the human body. The brain and spinal cord constitute the Central Nervous System which receives information from all parts of the body and integrates it. (a) How is the brain protected from shocks and injurie

In animals the control and coordination is provided by nervous and muscular tissues. Nervous tissue is made of an organized network of nerve cells or neurons. In human beings, thinking is a complex activity which involves more complex mechanisms and neural connections. These are concentrated in the brain which is the main coordinating centre of the human body. The brain and spinal cord constitute the Central Nervous System which receives information from all parts of the body and integrates it. (a) How is the brain protected from shocks and injuries? (b) Write the main functions of (i) sensory neuron and (ii) motor neuron in a reflex arc. (c) Which part of the brain is involved in activities like (i) picking a pencil and (ii) vomiting? State whether these actions are voluntary or involuntary.

When a ray of light moving in a medium enters obliquely into another medium, it bends from its path. This phenomenon is called refraction of light. The ability of a medium to refract light is also expressed in terms of optical density. It is not the same as mass density. We use the terms refractive index of medium A is more than the refractive index of medium. Thus a ray of light travelling from a rarer medium to a denser medium slows down and bends towards the normal. (a) Define the term absolute refractive index of a medium. (b) Absolute refractive indices of water and glass are $3/4$ and $2/3$ respectively. (i) In which one of the two media is the speed of light more? (ii) If a ray of light enters obliquely from glass to water, will it bend towards the normal or away from the normal? (c) The absolute refractive indices of water and glass are $3/4$ and $2/3$ respectively. If the speed of light in glass is $2 \times 10^8$ m/s, find the speed of light in (i) water and (ii) vacuum.

A basic substance is used to treat a honey-bee sting. Why?

(i) Define water of crystallisation. (ii) Write the chemical name and formula of a compound having water of crystallisation in its molecule and appears blue. (iii) Write the chemical formula of bleaching powder. Write a balanced chemical equation of the reaction involved in its preparation. List its three uses.