Class 8, 10: Science - Uses of Some Common Metals and Non-Metals

Uses of Some Common Metals and Non-Metals

USES OF SOME COMMON METALS

Metal	Main Uses
Iron	Bridges, Train tracks, Construction Bars, Steel, Engine Parts, Iron sheets etc.
Copper	Electrical Wires, Utensils, Coins etc.
Aluminium	Electric Wires, Utensils, Airplanes, Metallic Paints, Foil for packaging etc.
Silver	Jewellery, Electroplating, photography, Utensils, Coins, silvering of mirrors etc.
Gold	Jewellery and Decorations, Coins
Lead	Batteries, Alloys, Paints, Alloys like solder, Protective screen for X-Rays etc.
Mercury	Thermometers, Barometers, Dental amalgams etc.

CBSE Class 10 - Science- SA1- Sample Question Paper (2016)

CBSE Class 10 - Science- SA1- Sample Question Paper (2016) 

CBSE Class 10 - Science - CH7: Control and Coordination (VSQA)

CONTROL AND COORDINATION

Very Short Question And Answers

Q1: Which chemical induces artificial ripening of fruits?

Answer: Ethylene


Q2: What is stimulus?

Answer: The changes in the environment to which an organism responds and reacts is called stimulus.


Q3: Name the longest cell present in the human body.

Answer: Neuron is the longest cell in the human body.


Q4: Give examples of glands which act as both endocrine and exocrine.

Answer: Pancreas, Testes, Ovaries


Q5: What are nastic movements?

Answer: Movements of plants which are independent of stimuli are called nastic movements. e.g. movement by Touch-Me-Not (Mimosa) plant i.e. leaves close or droop when touched.


Q6: Where do you find gustatory receptors?

Answer: On the tongue.


Q7: What do olfactory receptors detect?

Answer: They detect smell.


Q8: Name the hormone released by thyroid gland.

Answer: Thyroxin.


Q9: Where is Hypothalmus is located?

Answer: In the brain.

CBSE Class 10 - Physics - CH 12 Electricity (Worksheet)

Electricity

Worksheet

Fill in the blanks

1. The source of all electricity is ______. It’s SI unit is _________.


2. The net charge flowing through a cross section of a conductor in unit time is called ________.


3. Electric potential difference between points in an electric circuit is the ______ _______ to move a unit charge from one point to other. i.e. 1V = ____/1C.


4. Current is measured in Amperes using _______.


5. If 90 coulombs charge passes through the conductor for 5 minutes, then the current in the conductor is _____.


6. A _________ is an electronic measuring instrument the combines several measuring functions (electric potential difference, electric current and electric resistance) in one unit.

CBSE Class 10 - Science- SA2- Sample Question Paper (2016)

CBSE Class 10 - Science- SA2- Sample Question Paper (2016) 

CBSE Class 10 - Biology - Heredity and Evolution - Do Not Miss These Important Definitions and Terms

Heredity and Evolution

Important Definitions and Terms

Q1: Define Genetics

Answer: Genetics is the branch of Biology which deals with the study of heredity and variation.


Q2: Define Heredity

Answer: Heredity refers to process by which certain features (inheritable) are transmitted from parent to offspring.


Q3: Define Variation

Answer: Offspring of same parents do not exactly resemble each other as well to their parents. It is called variation.


Q4: What are analogous organs?

Answer: The organs that have same functions but different structures and origin are called analogous organs. e.g. the wings of a bat and the wings of an insect are analogous.


Q5: What are homologous organs?

Answer: The organs that have the same structure, origin and components but may be performing different functions are called homologous organs. Eg: hands of a human and the forelimbs of a horse.


Q6: What are vestigial organs?

CBSE Class 10 - Science- SA2- Sample Question Paper (2016) and Marking Scheme

CBSE Class 10 - Science- SA2- Sample Question Paper (2016) and Marking Scheme

CBSE Class 10 - Science - Four New Elements Added In Periodic Table

Four New Elements Added In 

Periodic Table

Time to update Chemistry Textbooks. On December 30, IUPAC completes the verification of discoveries of four new chemical elements. It completes the 7 periodic row.

The atomic numbers of these four new elements are 113, 115, 117 and 118. Soon the new names will be given to these elements. At present these elements have temporary names i.e.

Ununtrium 113, 
Ununpentium 115, 
Ununseptium 117, 
Ununoctium 118 

CBSE Class 10 - Science - CH 16 - Management Of Natural Resources (Question Bank)

 Management Of Natural Resources 

Nature Conservation is Our Duty

(Question Bank)

Very Short Questions (1 Mark Each)

Q1: What is a natural resource? Give two examples.

Q2: Define sustainable development.

Q3: What does the three R’s stand for to save the environment?

Q4: What do you mean by water – shed management?

Q5: Name the award recently instituted by govt. of India in the memory of Amrita Devi Bishnoi.

Q6: Name the bacteria whose presence in the water indicates its contamination with disease causing microbes.

Q7: Define Bio-diversity.

Q8: Why fossil fuels should be used judiciously?

Q9: Which canal has brought greenery to the areas of Rajasthan?

Q10: State the advantage of constructing a dam across a river?

Q11: Name the place where “Chipko Andolan” organised.

CBSE Class 10 - Physics - Reflection of Light By Plane and Spherical Mirrors (V Short Q and A)

Reflection of Light By Plane and Spherical Mirrors

Laughing Mirrors use combination of Spherical Mirrors and Plane Mirrors.
Is this image real or virtual?

Very Short Question Answers (Based on NCERT Chapter)

Q1: What is the position of the object, when we get a diminished image with a concave mirror?

Answer: Beyond C (centre of curvature)

Q2: What are Marginal rays?

Answer: The rays which strike the mirror surface near the periphery are called marginal rays.

Q3: What type of rear mirrors are used by drivers in automobiles?

Answer: Convex mirrors

Q4: What is the relation between the radius of curvature (R) and focal length (f) of a concave mirror?

Answer: R = 2f

Q5: What is a focal length in case of spherical mirrors?

Answer: It is the distance between focal length and focus.

Q6: An object is moving with a speed v towards a plane mirror, what is the speed of the image?

CBSE Class 10 - Biology - CH8 - How do Organisms Reproduce? (Very Short Q and A)

How do Organisms Reproduce?

Very Short Q & A Based on CBSE Question Papers 

Q1: Name the scientist who used the Latin phrase "Omnis cellula e cellula," means "Every Cell From a Cell"?

Answer: Rudolf Virchow, a German Scientist who emphasised that cell produces cells.


Q2: Does Cell Division play an important role in reproduction?

Answer: Yes. It plays important role in both prokaryotes and eukaryotes. It is important in following two ways:
i.  gives rise to a new organism or daughter cell.
ii. in multicellular prokaryotes, cell division renews and repairs cells that die from wear and tear.


Q3: Give an example cell division occurs in human body for continuity of life?

Answer: Bone marrow continuously produce new blood cells.


Q4: What is the crucial function of cell division?

Answer: To pass genetic material (DNA copy) to offspring cellular apparatus.


Q5: What are the types of cell division? Give examples of each

Answer: There are two types of cell division:
i.  Mitotis : This cell division occurs in most of the cells of the body. Parent cells divides into two (or more) offspring cells passing on identical copies of DNA (genetic material).
ii Meosis: This cell division occurs in cells of reproductive organs (called male and female gametes). Each offspring cell contains half copy of DNA material froms its parent cell. When these male and female gametes fuse together, it gives rise to new organism.

CBSE Class 10 - Science- SA1- Sample Question Paper (2015-16) - Set2

CBSE Class 10 - Science- SA1- Sample Question Paper (2015-16) Second Set

CBSE Class 10 - Science- SA1- Sample Question Paper (2015-16)

CBSE Class 10 - Science- SA1- Sample Question Paper (2015-16)

CBSE Class 10 - Science - 1 Mark Questions Asked in Previous Question Papers (SA1 2012-2014)

Class X Science - SA1 - 1 Mark Questions

Questions Asked in Question Papers From 2012 To 2014

Q1 (2012): Name the sensory receptor found in the nose.

Answer: Olfactory receptors to detect the smell


Q2(2012): Name the sensory receptor found on the tongue.

Answer: Gustatory receptor to detect taste.


Q3(2012): Mention the angle between a current carrying conductor and magnetic field for which the force experienced by this current conductor placed in the magnetic field is the largest.

Answer: The force will be the largest when current carrying conductor and magnetic field direction is at a right angle to each other.


Q4(2012): Name a metal which is preserved in kerosene.

Answer: Sodium


Q5(2012): Name a metal which can melt while kept on a palm.

Answer: Gallium and Cesium


Q6(2012): Name the part of the brain which controls voluntary action.

Answer: Cerebrum or Forebrain

CBSE Class 10 - Science - SA1 - Sample Question Paper (2013-14)

Class 10 - Science -
SA1 - Question Paper (2013)

Time Allowed: 3 Hours                                                                                Maximum Marks: 90

---

General Instructions:
(i) The Question Paper comprises of two sections, A and B. Attempt both sections.
(ii) All questions are compulsory
(iii) All questions of Section A and all questions of Section B are to be attempted separately.
(iv) Question numbers 1 to 3 in Section A carry one mark each. These questions are to be answered in one word or in one sentence.
(v) Question numbers 4 to 6 in Section A are three marks questions. Answer each in about 30 words each.
(vi) Question Numbers 7 to 18 in Section A are three marks each. Answer each question not more than 50 words.
(vii) Questions 19 to 24 in section A are five marks each. Answer each question in not more than 70 words.
(viii) Questions numbers 25 to 33 in section B are multiple choice questions based on practical skills. Each question carries one mark.Select the most appropriate choice from the given choices.
(ix) Question Numbers 34 to 36 in Section B are questions based on practical skills and are two marks.

SECTION A

Q1:	Write the relation between electric power (W) of a device with potential difference (volt) across it and current (amp) flowing through it.	1
Q2:	Name two parts which constitute the central nervous system.	1
Q3:	Write the characteristic features of the micro organisms which help in the production of biogas in a biogas plant.	1
Q4:	Two solution A and B have pH 3 and 5 respectively. Which of the two solutions has more hydrogen ion concentration and which one is more acidic? Give reason for your answer.	2
Q5:	Give reason for the following: (a) Sodium metal is kept immersed in kerosene. (b) Blue colour of copper sulphate solution disappears when some aluminium powder is added in it.	2
Q6:	Give two reasons why different electrical appliances in a domestic circuit are connected in parallel.	2
Q7:	(i) Give reason ,”Magnetic field is strongest near the pole.” (ii) Describe an activity to show that magnetic field is strongest near poles of a bar magnet.

CBSE Class 10 Science - CH 14 - Sources Of Energy (Short Q and A)

Sources Of Energy

Short Q & A based on NCERT Chapter Source Of Energy

Q1: What are the important limitations of wind energy?

Answer:

1. Cost of maintaining wind energy is high
2. Wind energy farms can be established only at places where wind blows for greater part of year and speed is greater than 15 kmph.

Q2: What are hot spots?

Answer: Due to geological changes molten rock forms in deeper hot region of the earth's crust are pushed upwards which gets collected at some depth below the earth surface. These regions or places are called hot spots.


Q3: State one limitation in harnessing geothermal energy.

Answer: Geothermal hot spots are scattered. Usually these are some distance away from the area that needs energy.


Q4: What are the limitations in harnessing tidal energy?

Answer:

Few suitable places for building tidal energy farms.
Rise and fall of water is not enough to generate electricity on large scale.

CBSE Class 10 - Science - SA1 Question Paper (2014)

Science - Question Paper (2014)

Class 10 Science  Question Paper (SA1 - September 2014)

Time Allowed: 3 Hours                                                                            Maximum Marks: 90

---

General Instructions:
(i) The Question Paper comprises of two sections, A and B. Attempt both sections.

(ii) All questions are compulsory

(iii) All questions of Section A and all questions of Section B are to be attempted separately.

(iv) Question numbers 1 to 3 in Section A carry one mark each. These questions are to be answered in one word or in one sentence.

(v) Question numbers 4 to 6 in Section A are three marks questions. Answer each in about 30 words each.

(vi) Question Numbers 7 to 18 in Section A are three marks each. Answer each question not more than 50 words.

(vii) Questions 19 to 24 in section A are five marks each. Answer each question in not more than 70 words.

(viii) Questions numbers 25 to 33 in section B are multiple choice questions based on practical skills. Each question carries one mark.Select the most appropriate choice from the given choices.

(ix) Question Numbers 34 to 36 in Section B are questions based on practical skills and are two marks.

SECTION A

Q1:	Name the two components of peripheral nervous system?	1
Q2:	What are hot spots inside the earth's crust?	1
Q3:	A charge of 150 C flows through a wire in one minute. Find the electric current flowing through it.	1
Q4:	Explain why an aqueous solution of sodium sulphate is neutral while an aqueous solution of sodium carbonate is basic in nature.	2
Q5:	When hydrogen gas is passed over heated copper (II) oxide, copper and steam are formed. Write the balanced chemical equation for this reaction and state: (i) the substance oxidised. (ii) the substance reduced in the reaction.	2
Q6:	Why do herbivores have longer, smaller intestine than carnivores?

CBSE Class 10 Science CHEMICAL REACTIONS AND EQUATIONS - Board Questions (2008-2014) and Answers

CHEMICAL REACTIONS AND EQUATIONS

Board Questions (2008-2014) and Answers

Q1(2008): What happens chemically when quick lime is added to water?

Answer: Quick lime is CaO which reacts vigorously with water to produce slaked lime (calcium hydroxide) releasing a large amount of heat.

                           CaO(s) + H₂O(l) → Ca(OH)₂(aq)

Q2: A student burns magnesium ribbon in the lab and observes a white powder falling on the table. What type of reaction has taken place and name the white powder?

Answer: It is a chemical reaction. The white powder formed is magnesium oxide (MgO).

Q3: What are the essentials of a chemical reaction?

Answer:

• It should be balanced and confirm to the law of conservation of matter
• It should be molecular
• It must refer to an actual chemical equation

Q4: How will you test for the gas which is liberated when hydrochloric acid reacts with an active metal?

Answer: When a burning match stick is brought near the mouth of the test tube in which reaction is taking place, it will burn with popping sound. It detects the presence of hydrogen (H₂) gas.

Q5: What change in colour is observed when white silver chloride is left exposed to sunlight? What type of chemical reaction is this?

Answer: White silver chloride turns grey in sunlight. This is due to the decomposition of silver chloride into silver and chlorine by light.It is a photo-chemical decomposition reaction.

                2AgCl(s) —^Sunlight—→ 2Ag(s) + Cl₂(g)

Q6: Why is respiration considered as exothermic process?

Answer: In respiration heat is released so it is termed as an exothermic reaction.

                   C₆H₁₂O₆ + 6O₂ —→ 6CO₂ + 6H₂O + energy

Q7(2010):What is meant by skeletal equation?

Answer: The equation which is unbalanced because the mass is not the same on both sides of the equation, is a skeletal chemical equation for a reaction.

During exam, try to write chemical equations and chemical formulae in your answers wherever possible. It enhances visibility and gives you more scores.

Q8: Identify the type of reaction in the following example:

Na₂SO₄(aq) + BaCl₂(aq) —→ BaSO₄(s) + 2NaCl(aq)

Answer: A double displacement reaction.

Q9: Why are bags of chips flushed with nitrogen gas?

Answer: Chips manufacturers usually flush bags of chips with gas such as nitrogen to prevent the chips from getting oxidised.

Q10 : What is precipitation reaction?

CBSE Class 10 - Science - CH2 - Acids, Bases and Salts (Worksheet)

Acids, Bases and Salts

credits:clker.com

Worksheet

Fill in the Blanks

1. Blue litmus changes into red colour in the presence of_______.

2. The acid present in lemon juice is _______.

3. Red litmus changes into blue colour in the presence of ______.

4. The chemical name of Plaster of Paris is ___________ and its chemical formula is ____________.

5. Methyl orange gives __________ in basic medium while phenolphthalein gives _______.

6. Example for strong acid is ________.

7. Example for weak acid is ________

8. Example for strong base is_______.

9. Example for weak base is ____________

CBSE Class 6-12 - Science - Fathers in Biology

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Fathers of Various Branches in Biology

Aristotle - Father of Biology
credits: wikipedia

Num.	Branch of Biology	Name
1	Father of Biology	Aristotle
2	Father of Zoology	Aristotle
3	Father of Botany	Theophrastus
4	Father of Taxonomy	Carl Linnaeus
5	Father of Plant Physiology	Stephen Hales
6	Father of Bacteriology	Louis Pastuer
7	Father of Microbiology	Leeuwenhoek
8	Father of Immunology	Edward Jenner
9	Father of Cytology	Robert Hooke
10	Father of Mycology	Micheli
11	Father of Genetics	G J Mendel
12	Father of Experimental Genetics	T. H. Morgan
13	Father of Bryology	Johann Hedwig
14	Father of Eugenics	Francis Galton
15	Father of Microscopy	Marcello Malphigi
16	Father of Bio-diversity	E.O. Wilson
17	Father of Medicine	Hippocrates
18	Father of modern Anatomy	Andreas Vesalius
19	Father of Radiation Genetics	H. J. Muller