Mathematics – Chapter 23: Probability

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Mathematics – Chapter 14: Linear Equation in One Variable

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Mathematics – Chapter 10: Direct and Inverse Variations

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Mathematics – Chapter 13: Factorization

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Mathematics – Chapter 22: Data Handling

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Happy Republic Day!

Physics – Chapter 6: Heat Transfer

• Q1. A matter is something that has mass, occupies space and can be perceived by our senses. It is composed of tiny particles called molecules.
• Q2. Name the three states of matter and distinguish them on the basis of their 
  • (i) volume, and 
  • (ii) shape
• Q3. Distinguish between liquid and vapour (or gas) states of matter on the basis of the following factors:
  • (a) Arrangement of molecules
  • (b) Inter-molecular separation
  • (c) Inter-molecular force and
  • (d) Kinetic energy of molecules
• Q4. Do all the molecules of a liquid take part in evaporation? If not, explain your answer.

Physics – Chapter 6: Heat Transfer

• Q1. A matter is something that has mass, occupies space and can be perceived by our senses. It is composed of tiny particles called molecules.
• Q2. Name the three states of matter and distinguish them on the basis of their 
  • (i) volume, and 
  • (ii) shape
• Q3. Distinguish between liquid and vapour (or gas) states of matter on the basis of the following factors:
  • (a) Arrangement of molecules
  • (b) Inter-molecular separation
  • (c) Inter-molecular force and
  • (d) Kinetic energy of molecules
• Q4. Do all the molecules of a liquid take part in evaporation? If not, explain your answer.

Biology – Chapter 7: Nervous System

• Q1. Medulla oblongata controls
  • Smelling
  • Beating of heart and respiratory movement
  • Intelligence and will power
  • Balancing of the body
• Q2. Balance of body is controlled by
  • Spinal cord
  • Cerebellum
  • Cerebrum
  • Medulla
• Q3. The smell of good food causes watering of your mouth. It is
  • Natural reflex
  • Acquired reflex
  • Inborn reflex
  • Ordinary reflex
• Q4. You are driving your bicycle at a fast speed. Suddenly, a small boy comes in front of your cycle and without wasting any time in thinking, you immediately apply the brakes and the accident is avoided. What name is given to such an action ?
• Q5. Name the following :
  • (a) The long, extended process of a neuron
  • (b) The point of contact between two neurons
  • (c) The kind of nerve which carries both sensory and motor neurons
  • (d) The nerve which connects the eyes to the brain
  • (e) The nerve which connects the nose to the brain
  • (f) The nerve which connects the ears to the brain
  • (g) Two sub-divisions of the peripheral nervous system
  • (h) Two parts of the autonomic nervous system

Chemistry – Chapter 3: Elements, Compounds and Mixtures

• Q1. Classify the following substances into compounds and mixtures:
  • Carbon dioxide, air, water, milk, common salt, blood, fruit juice, iron sulphide.
• Q2. Give one example for each of the following types of mixtures.
  • (a) solid-solid homogeneous mixture
  • (b) solid-liquid heterogeneous mixture
  • (c) miscible liquids
  • (d) liquid-gas homogeneous mixture
• Q3. Suggest a suitable technique to separate the constituents of the following mixtures. Also give the reason for selecting the particular method.
  • (a) Salt from sea water
  • (b) Ammonium chloride from sand
  • (c) Chalk powder from water
  • (d) Iron from sulphur
  • (e) Water and alcohol
  • (f) Sodium chloride and potassium nitrate
  • (g) Calcium carbonate and sodium chloride
• Q4. Why is it necessary to separate the constituents of a mixture?
• Q5. Choose the most appropriate answer from the options given below:
• A mixture of sand and ammonium chloride can be separated by
  • filtration
  • distillation
  • sublimation
  • crystallization

Chemistry – Chapter 5: Language of Chemistry

• Q1. What are the ways by which a chemical equation can be made more informative?
• Q2. State the law of conservation of mass.
• Q3. Differentiate between:
  • (a) Reactants and Products
  • (b) A balanced and an unbalanced chemical equation

Chemistry – Chapter 5: Language of Chemistry

• Q1. Define:
  • (a) Radical
  • (b) Valency
  • (c) Molecular formula
• Q2. The valency of aluminium is 3. Write the valency of other radicals present in the following compounds.
  • (a) Aluminium chloride
  • (b) Aluminium oxide
  • (c) Aluminium nitride
  • (d) Aluminium sulphate
• Q3. 
  • (a) What is a chemical equation?
  • (b) Why is it necessary to balance a chemical equation?
  • (c) What are the limitations of a chemical equation?
• Q4. Differentiate between:
  • (a) Reactants and Products
  • (b) A balanced and an unbalanced chemical equation
• Q5. Balance the following equations:
  • N2 + H2 ⟶ NH3
  • H2 + O2 ⟶ H2O
  • Na2O + H2O ⟶ NaOH
  • CO + O2 ⟶ CO2
  • Zn + HCl ⟶ ZnCl2 + H2
• Q6. Write balanced chemical equations for the following word equations:
  • Iron + Chlorine ⟶ Iron(III) chloride
  • Magnesium + dil. sulphuric acid ⟶ Magnesium sulphate + hydrogen
  • Magnesium + oxygen ⟶ Magnesium oxide
  • Calcium oxide + water ⟶ Calcium hydroxide
  • Sodium + Chlorine ⟶ Sodium chloride

Chemistry – Chapter 7: Hydrogen

• Q1. 
  • (a) Name a process by which hydrogen gas is manufactured.
  • (b) Give equations for the reactions.
  • (c) How is hydrogen separated from carbon dioxide and carbon monoxide?
• Q2. State four uses of hydrogen.
• Q3. Define:
  • (a) catalytic hydrogenation
  • (b) oxidation
  • (c) reduction
  • (d) redox reaction
• Q4. Equal volumes of hydrogen and chlorine are exposed to diffused sunlight to prepare
  • hydrogen chloride
  • water
  • sodium hydroxide
  • hydrochloric acid

Biology – Chapter 4: Ecosystems

• Q1. The term “ecosystem” is derived from the Greek word “Oikos” meaning.
  • Body weight
  • Food
  • House
  • Size
• Q2. The number of steps in a food chain can never be more than
  • Four
  • Five
  • Six
  • Seven
• Q3. Rewrite the following in their correct sequence in a food chain:
  • (a) Snake → Grasshopper → Grass → Frog
  • (b) Grass → Tiger → Deer
  • (c) Snake → Peacock → Rat → Wheat
• Q4. Differentiate among primary, secondary and tertiary consumers. Give one example each in a food chain.
• Q5. Define the terms 
  • (a) Flora and 
  • (b) Fauna.
• Q6. List any three members each of the flora and fauna of tropical rain forests.

Biology – Chapter 5: Endocrine Systems and Adolescence

• Q1. Which one of the following hormones converts excess of glucose into glycogen
  • Glucagon
  • Thyroxine
  • Insulin
  • Adrenaline
• Q2. Which one of the following glands is also called the master gland :
  • Pituitary gland
  • Adrenal gland
  • Thyroid gland
  • Ovary
• Q3. The emergency hormone to face the danger or to fight is secreted by;
  • Islets of Langerhans
  • Adrenal cortex
  • Pituitary
  • Adrenal medulla
• Q4. What is the difference between an exocrine gland and an endocrine gland ?
• Q5. Why is Pituitary gland called the “master gland”?
• Q6. Briefly write about the importance of physical hygiene during adolescence.
• Q7. Briefly discuss any four activities which can be practiced to overcome stress.

Biology – Chapter 6: The Circulatory System

• Q1. Define the terms :
  • (a) Circulatory system
  • (b) Blood
  • (c) Lymph
  • (d) Artificial pacemaker
• Q2. Differentiate between the following pairs on the basis of what is indicated within the brackets:
  • (a) Pulmonary artery and pulmonary vein (kind of blood)
  • (b) Artery and vein (direction of blood flow)
  • (c) Closed and open vascular system (definition)
  • (d) Bicuspid and tricuspid valve (location)
  • (e) Blood and lymph (composition)
• Q3. Write important role/roles of each:
  • (a) Pericardial fluid
  • (b) Aorta
  • (c) Vena cava
• Q4. Give the functions of lymph.

Physics – Chapter 2: Physical Quantities and measurement

• Q1. The relative density of alcohol is 0.8. Its density is:
  • 0.8
  • 800 kg m-3
  • 800 g cm-3
  • 0.8 kg m-3
• Q2. A block of wood of density 0.8 g cm-3 has a volume of 60 cm-3. The mass of block is:
  • 60.8 g
  • 75 g
  • 48 g
  • 0.013 g
• Q3. A density bottle has a marking 25 mL on it. It means that:
  • the mass of density bottle is 25 g.
  • the density bottle will store 25 mL of any liquid in it.
  • the density bottle will store 25 mL of water, but more volume of liquid denser than water.
  • the density bottle will store 25 mL of water, but more volume of a liquid lighter than water.
• Q4. The correct statement is:
  • The buoyant force on a body is equal to the volume of the liquid displaced by it.
  • The buoyant force on a body is equal to the volume of the body.
  • The buoyant force on a body is equal to the weight of the liquid displaced by it.
  • The buoyant force on a body is always equal to the weight of the body.
• Q5. A piece of wood floats on water. The buoyant force on wood will be:
  • zero
  • more than the weight of the wood piece.
  • equal to the weight of the wood piece.
  • less than the weight of the wood piece.
• Q6. The weight of a body is more than the buoyant force experienced by it, due to a liquid. The body will:
  • sink
  • float with its some part outside the liquid.
  • float just below the surface of liquid.
  • float with whole of its volume above the surface of liquid.
• Q7. What is a density bottle? How is it used to find the density of a liquid?
• Q8. Define the term relative density of a substance.

Chemistry – Chapter 7: Hydrogen

• Q1. Fill in the blanks:
  • (a) Hydrogen is …………… than air.
  • (b) Hydrogen is …………… soluble in water.
  • (c) Hydrogen burns with a …………… flame and …………… sound is heard.
  • (d) A metal …………… hydrogen in the reactivity series gives hydrogen with …………… .
  • (e) Hydrogen reacts with metal oxides to form …………… and …………… .
  • (f) Oxidation is the removal of …………… or addition of …………… .
  • (g) In redox reactions, oxidation and reduction occurs …………… .
• Q2. Complete and balance the following equations:
  • (a) H2 + ……………….. ⟶ 2HCl
  • (b) H2 + S ⟶ ……………………
  • (c) Zn + ……………. ⟶ ZnCl2 + H2
  • (d) CuO + ………….. ⟶ Cu + ………….
  • (e) Fe + H2O ⟶ …………….. + ……………
  • (f) K + H2O ⟶ ……………… + ……………
• Q3. Give reasons for the following:
  • (a) Hydrogen can be used as a fuel.
  • (b) Though hydrogen is lighter than air it cannot be collected by downward displacement of air.
  • (c) A pop sound is produced when hydrogen gas is burnt.
  • (d) Helium has replaced hydrogen in weather observation balloons.
  • (e) Nitric acid is not used for the preparation of hydrogen gas.

Physics – Chapter 2: Physical Quantities and measurement

• Q1. A given quantity of a liquid is heated. Which of the following quantity will vary and how?
  • (a) mass
  • (b) volume
  • (c) density
• Q2. Describe an experiment to determine the density of the material of a coin.
• Q3. What is the unit of relative density?
• Q4. Distinguish between density and relative density.
• Q5. The diagram given below shows a body floating in three different liquids A, B and C at different levels.
  • (a) In which liquid does the body experience the greatest buoyant force?
  • (b) Which liquid has the least density?
  • (c) Which liquid has the highest density?

Physics – Chapter 1: Matter

• Q1. Write true of false for each statement:
  • (a) The temperature of a substance remains unaffected during its change of state.
  • (b) Ice melts at 100°C.
  • (c) Water at 100°C has more heat than steam at 100°C.
  • (d) Evaporation of a liquid causes cooling.
  • (e) Water evaporates only at 100°C.
  • (f) Boiling takes place at all temperatures.
  • (g) Evaporation takes place over the entire mass of the liquid.
  • (h) The process of a gas converting directly into solid is called vaporization.
  • (i) At high altitudes, water boils above 100°C.
  • (j) The melting point of ice is 0°C.
• Q2. Fill in the blanks:
  • (a) Evaporation takes place at …………… temperatures.
  • (b) …………… process is just the reverse of melting.
  • (c) …………… is a process that involves direct conversion of a solid into its vapour on heating.
  • (d) The temperature at which a solid converts into a liquid is called its …………… .
  • (e) The smallest unit of matter that exists freely in nature is called …………… .
  • (f) Molecules of a substance are always in a state of …………… and so they possess …………… .
  • (g) Inter-molecular space is maximum in …………… less in …………… and the least in …………… .
  • (h) Inter-molecular force of attraction is maximum in …………… , less in …………… and the least in …………… .
• Q3. Define the term matter. What is it composed of?
• Q4. What do you mean by ‘the change of state’? Write the flowchart showing the complete cycle of change of state.

Physics – Chapter 2 – Physical Quantities and measurement

• Q1. The correct statement is:
  • The buoyant force on a body is equal to the volume of the liquid displaced by it.
  • The buoyant force on a body is equal to the volume of the body.
  • The buoyant force on a body is equal to the weight of the liquid displaced by it.
  • The buoyant force on a body is always equal to the weight of the body.
• Q2. A piece of wood floats on water. The buoyant force on wood will be:
  • zero
  • more than the weight of the wood piece.
  • equal to the weight of the wood piece.
  • less than the weight of the wood piece.
• Q3. The weight of a body is more than the buoyant force experienced by it, due to a liquid. The body will:
  • sink
  • float with its some part outside the liquid.
  • float just below the surface of liquid.
  • float with whole of its volume above the surface of liquid.
• Q4. The density of brass is 8.4 g cm-3. What do you mean by this statement?
• Q5. How does the density of a liquid (or gas) vary with temperature?
• Q6. What is a density bottle? How is it used to find the density of a liquid?

Chemistry – Chapter 2: Physical and Chemical Changes

• Q1. Define:
  • (a) a physical change
  • (b) a chemical change
• Q2. Classify the following as a physical or a chemical change:
  • (a) Drying of wet clothes.
  • (b) Manufacture of salt from sea water.
  • (c) Butter getting rancid.
  • (d) Boiling of water
  • (e) Burning of paper
  • (f) Melting of wax
  • (g) Burning of coal
  • (h) Formation of clouds
  • (i) Making of a sugar solution
  • (j) Glowing of an electric bulb
  • (k) Curdling of milk
  • (l) Rusting of iron
  • (m) Roasting of potatoes
  • (n) Formation of alloys
• Q3. Give reasons:
  • (a) Freezing of water to ice and evaporation of water are physical changes.
  • (b) Burning of a candle is both a physical and a chemical change.
  • (c) Burning of paper is a chemical change.
  • (d) Cutting of a cloth piece is a physical change, though it cannot be reversed.

Chemistry – Chapter 3: Elements, Compounds and Mixtures

• Q1. Name:
  • (a) a soft metal
  • (b) a metal which is brittle
  • (c) a non-metal which is lustrous
  • (d) a liquid metal
  • (e) a metal which is a poor conductor of electricity
  • (f) a non-metal which is a good conductor of electricity
  • (g) a liquid non-metal
  • (h) the hardest naturally occurring substance
  • (i) an inert gas
• Q2. Classify the following substances into compounds and mixtures:
  • Carbon dioxide, air, water, milk, common salt, blood, fruit juice, iron sulphide.
• Q3. Suggest a suitable technique to separate the constituents of the following mixtures. Also give the reason for selecting the particular method.
  • (a) Salt from sea water
  • (b) Ammonium chloride from sand
  • (c) Chalk powder from water
  • (d) Iron from sulphur
  • (e) Water and alcohol
  • (f) Sodium chloride and potassium nitrate
  • (g) Calcium carbonate and sodium chloride

Chemistry – Chapter 3: Elements, Compounds and Mixtures

• Q1. Give two examples for each of the following:
  • (a) Metals
  • (b) Non-metals
  • (c) Metalloids
  • (d) Inert gases
• Q2. Differentiate between:
  • (a) Pure and impure substances
  • (b) Homogeneous and heterogeneous substances
• Q3. Write the chemical name of the following and also give their molecular formulae:
  • (a) Baking soda
  • (b) Vinegar
  • (c) Marble
  • (d) Sand

Chemistry – Chapter 4 – Atomic Structure

• Q1. Give the following a suitable word/phrase.
  • (a) The subatomic particle with negative charge and negligible mass.
  • (b) Protons and neutrons present in the nucleus.
  • (c) The electrons present in the outermost shell.
  • (d) Arrangement of electrons in the shells of an atom.
  • (e) The number of protons present in the nucleus of an atom.
  • (f) The sum of the number of protons and neutrons of an atom.
  • (g) Atoms of same element with same atomic number but a different mass number.
  • (h) The smallest unit of an element which takes part in a chemical reaction.
• Q2. Name three fundamental particles of an atom. Give the symbol with charge on each particle.
• Q3. Define the following terms:
  • (a) Atomic number
  • (b) Mass number
  • (c) Nucleons
  • (d) Valence shell
• Q4. What is variable valency? Name two elements having variable valency and state their valencies.

Physics – Chapter 6 – Heat Transfer

• Q1. Write true or false for each statement. Write the correct statement if it is false.
  • (a) Evaporation is rapid on a wet day.
  • (b) Evaporation takes place only from the surface of a liquid.
  • (c) All molecules of a liquid take part in the process of evaporation.
  • (d) Temperature of a liquid rises during boiling or vaporization.
  • (e) All molecules of a liquid take part in boiling.
  • (f) Boiling is a rapid phenomenon.
  • (g) All solids expand by the same amount when heated to the same rise in temperature.
  • (h) Telephone wires are kept tight between the two poles in winter.
  • (i) Equal volumes of different liquids expand by different amounts when they are heated to the same rise in temperature.
  • (j) Solids expand the least and gases expand the most on being heated.
  • (k) A mercury thermometer makes use of the property of expansion of liquids on heating.
  • (l) Kerosene contracts on heating.
• Q2. Fill in the blanks:
  • (a) Boiling occurs at …………… .
  • (b) Evaporation takes place at …………… .
  • (c) The molecules of liquid …………… heat from surroundings in evaporation.
  • (d) Heat is …………… during boiling.
  • (e) Cooling is produced in …………… .
  • (f) A longer rod expands …………… than a shorter rod on being heated to the same temperature.
  • (g) Liquids expand …………… than the solids.
  • (h) Gases expand …………… than the liquids.
  • (i) Alcohol expands …………… than water.
  • (j) Iron expands …………… than copper.
• Q3. Distinguish between liquid and vapour (or gas) states of matter on the basis of the following factors:
  • (a) Arrangement of molecules
  • (b) Inter-molecular separation
  • (c) Inter-molecular force and
  • (d) Kinetic energy of molecules

Physics – Ch 06 – Heat Transfer

• Q1. Write true or false for each statement:
  • (a) Evaporation is rapid on a wet day.
  • (b) Evaporation takes place only from the surface of a liquid.
  • (c) All molecules of a liquid take part in the process of evaporation.
  • (d) Temperature of a liquid rises during boiling or vaporization.
  • (e) All molecules of a liquid take part in boiling.
  • (f) Boiling is a rapid phenomenon.
  • (g) All solids expand by the same amount when heated to the same rise in temperature.
  • (h) Telephone wires are kept tight between the two poles in winter.
  • (i) Equal volumes of different liquids expand by different amounts when they are heated to the same rise in temperature.
  • (j) Solids expand the least and gases expand the most on being heated.
  • (k) A mercury thermometer makes use of the property of expansion of liquids on heating.
  • (l) Kerosene contracts on heating.
• Q2. During boiling or vaporization:
  • all molecules take part
  • temperature rises
  • no heat is absorbed
  • the average kinetic energy of molecules increases
• Q3. Two rods A and B of the same metal, same length, but one solid and other hollow, are heated to the same rise in temperature. Then:
  • the solid rod A expands more than the hollow rod B
  • the hollow rod B expands more than the solid rod A
  • the hollow rod B contracts, but the solid rod A expands
  • both the rods A and B expand the same
• Q4. Distinguish between liquid and vapour (or gas) states of matter on the basis of the following factors:
  • (a) Arrangement of molecules
  • (b) Inter-molecular separation
  • (c) Inter-molecular force and
  • (d) Kinetic energy of molecules

Physics – Chapter 3: Force and Pressure

• Q1. Fill in the blanks:
  • (a) 1 kgf = …………… N (nearly).
  • (b) Moment of force = …………… x distance of force from the point of turning.
  • (c) In a door, handle is provided …………… from the hinges.
  • (d) The unit of thrust is …………… .
  • (e) Thrust is the …………… force acting on a surface.
  • (f) Pressure is the thrust acting on a surface of …………… area.
  • (g) The unit of pressure is …………… .
  • (h) Pressure is reduced if …………… increases.
  • (i) Pressure in a liquid …………… with the depth.
  • (j) The atmospheric pressure on earth surface is nearly …………… .
• Q2. Select the correct alternative: To obtain a given moment of force for turning a body, the force needed can be decreased by:
  • applying the force at the pivoted point.
  • applying the force very close to the pivoted point.
  • applying the force farthest from the pivoted point.
  • none of the above.
• Q3. A body weighing 5 kgf, placed on a surface of area 0.1 sq. m, exerts a thrust on the surface equal to:
• Q4. How does the effect of a force differ when it is applied on
  • (a) a rigid body
  • (b) a non-rigid body?

Physics – Chapter 5 –  Light Energy

• Q1. A ray of light moving from an optically rarer to a denser medium:
  • bends away from the normal
  • bends towards the normal
  • remains undeviated
  • None of the above
• Q2. The property of splitting of white light into its seven constituent colours is known as:
  • rectilinear propagation
  • refraction
  • reflection
  • dispersion
• Q3. The image formed by a convex mirror is:
  • erect and diminished
  • erect and enlarged
  • inverted and diminished
  • inverted and enlarged
• Q4. State the speed of light in:
  • (a) air
  • (b) water and
  • (c) glass.
• Q5. Which is optically denser: water or air? Give reason.
• Q6. Describe an experiment to show that a light ray bends when it passes from one transparent medium into another transparent medium.
• Q7. A ray of light falls normally on a glass slab. What is the angle of incidence?

Mathematics – Chapter 11 – Algebraic Expressions

• Q1. Write the number of terms in each of the following polynomials.
  • (i) 5×2 + 3 x ax
  • (ii) ax ÷ 4 – 7
  • (iii) ax – by + y x z
  • (iv) 23 + a x b ÷ 2.
• Q2. Write the coefficient of :
  • (i) ab in 7abx ,
  • (ii) 7a in 7abx ;
  • (iii) 5×2 in 5×2 – 5x ;
  • (iv) 8 in a2 – 8ax + a ;
  • (v) 4xy in x2 – 4xy + y2.
• Q3. Find the total savings of a boy who saves ₹ (4x – 6y) ; ₹ (6x + 2y) ; ₹ (4y – x) and ₹ (y – 2x) for four consecutive weeks.