Acids, Bases and Salts Class X Important Questions and Answers

1.What is efflorescence? Give an example?
Ans. It in the process of the loss of molecules of water of crystallization from a substance when exposed to air for example

Chemical Reactions and Equations CLASS X Important questions

Q1. Why does not silver evolve hydrogen on reacting with dil H2SO4
Ans.Silver do not evolve hydrogen on reacting with dil.H2SO4 as silver is less reactive metal than hydrogen

Class 11 Maths Sets Important Questions

1.In a town of 10,000 families, it was found that 40% families buy newspaper A, 20% families buy newspaper B and 10% families buy n ewspaper C. 5% families buy A and B, 3% buy B and C and 4% buy A and C. If 2% families buy all the three papers. Find the no. of families which buy (i) A only (ii) B only (iii) none of A, B, and C.
2.
Two finite sets have m and n elements. The to tal no. of subsets of the first set is 56 more than the total no. of subsets of second set . Find the value of m and n.

3.In a survey of 100 students, the no. of students studying the various languages were found to be English only 18, English but not H indi 23, English and Sanskrit 8, English 26, Sanskrit 48, Sanskrit and Hindi 8, n o language 24. Find
(i) How many students were studying Hindi?
(ii) How many students were studying English and Hi ndi?
4. In a class of 50 students, 30 students like Hindi, 25 like science and 16 like both. Find the no. of students who like

(i) Either Hindi or science

(ii) Neither Hindi nor science.

5.In a class of 25 students, 12 have taken mathematic s, 8 have taken mathematics but not biology. Find the no. of students who have take n both mathematics and biology and the no. of those who have taken biology but not mathematics each student has taken either mathematics or biology or both.

6. These are 20 students in a chemistry class and 30 s tudents in a physics class. Find the number of students which are either in physics class or chemistry class in the following cases.

(i) Two classes meet at the same hour

(ii) The two classes met at different hours and ten students are enrolled in both the courses.

7. In a survey of 25 students, it was found tha t 15 had taken mathematics, 12had taken physics and 11 had taken chemistry, 5 had taken mat hematics and chemistry, 9 had taken mathematics and physics, 4 had taken physics and chemistry and 3 had taken all three subjects. Find the no. of students that had taken

(i) only chemistry

(ii) only mathematics

(iii) onl y physics

(iv) physics and chemistry but mathematics (v) ma thematics and physics but not chemistry
(vi) only one of the subjects
(vii) at le ast one of three subjects
(viii) None of three subjects.
8.A college awarded 38 medals in football, 15 in basketball and 20 in cricket. If these medals went to a total of 58 men and only thr ee men got medal in all the three sports, how many received medals in exactly t wo of the three sports?

9. In a survey of 60 people, it was found that 25 peop le read news paper H, 26 read newspaper T, 26 read newspaper I, 9 read both H and I, 11 read both H and T, 8 read both T and I, 3 read all three newspa per. Find
(i) The no. of people who read at least one of the newspapers.
(ii) The no. of people who read exactly one news pa per.

10.In a survey of 400 students in a school, 100 were list e d as taking apple juice, 150 as taking orange juice and 75 were listed as taking bo th apple as well as orange juice. Find how many students were taking neither apple ju ice nor orange juice.

11. A survey shows that 73% of the India ns like apple s , wherea s 65% like orange s . What % Indians like both apples and oranges?

12. In a school there are 20 teachers who teach mathematics or phys ics. Of these 12 teach mathematics and 4 teach both physics and math ematics. How many teach physics?

13. There are 2 00 individuals with a skin disorder, 120 had been e xposed to the chemical C 1 , 50 to chemical C 2 , and 30 to both the chemicals C 1 and C 2 . Find the number of individuals exposed to

(1) chemical C 1 but not chemical C 2

(2) chemical C 2 but not chemical C 1

(4) chemical C 1 or chemical C 2

14. In a survey it was found that 21 peoples liked prod uct A, 26 like d product B and 29 liked product C. If 14 people liked products A and B, 12 people like C and A, 14 people like B and C and 8 liked all the three produ cts. Find now many liked product C only.

Separation of Substances Class 6 Science

Important question and answers of Separation of Substances

CBSE Class 6 Science



1.The dust particles in the water can be helped to se ttle down faster by using
Ans.Alum

2.The process by which the unwanted solid particles a re removed from the liquid is called
Ans.Filtration

Sorting Materials into Groups Class 6 Science

Important questions and Answers of Sorting Materials into Groups

1.Fill in the blanks with suitable word/ words.
a. Making orderly arrangement of materials is called - --------------------.
b. Newspaper, a book, a copy, a diary are made up of - ----------------.
c. Substances that can burn easily are called -------- ---------.
d. A substance that allow light to pass is called ---- ---------------.
e. ------------------- gas is highly combustible.
(a) Classification (b) paper (c) combustible (d) tr ansparent (e) Hydrogen.

2.Fill in the blanks

Class 10 Science Life processes Important question and answers

1.What is the role of glomerulus in kidney?

Ans.Glomerulus is a group of capillaries present in the cup like Bowman’s Capsule. It receives blood from renal artery which brings excre tory wastes from body to the kidney. It filters water, salts, glucose, urea, the nitrogen containing end products of proteins and yellow bile compounds from the liver.

NCERT Solutions CBSE Class 10 Life processes Solutions

Here are the NCERT Solutions of Chapter 6 Life Processes

Page No. 95

Q1.Why is diffusion insufficient to meet the oxygen requirements of multicellular organisms like humans? 

Ans.As in multicellular organisms, all the cells are not in direct contact with environment,
simple diffusion does not meet the requirement of all the body cells.   


Q2.What criteria do we use to decide whether something is alive?

Ans.All  the  living  organism  must  have  movement  at  molecular  levels  along  with
respiration  and  other  life  process  like  nutrition, respiration,  transportation  and
excretion to be called alive.

CBSE Class 8 Cell Structure and Functions Important question and Answers

One Word Answers

1.The lowest level of organization of life is

Ans.Cellular level

CBSE Class 8 Science Synthetic Fibres and Plastics Important Question and Answers

 CBSE Class 8 Science Synthetic Fibres and Plastics Important Question and Answers

A.One word Answers

1.Polyester is a long chain polymer of a chemical substance called
Ans.Ester
2.A regenerated synthetic fibre is

Ans.Rayon

CBSE Class 8 Microorganisms Friend And Foe Important question and Answers

CBSE Class 8 Microorganisms Friend And Foe Important question and Answers

A.One Word Answers

1.Some microbes have a hard outer cover called :

Ans.Cyst

CBSE Class 8 Science Crop Production and Management

CBSE Class 08 Science Crop Production and Management Important question and Answers



A. One Word Answers

 1.Conversion of ammonia into nitrates is called

Ans.Nitrification

Class 6 Electricity and Circuits Question and Answers

A.One Word Answers
1.Combination of two or more cells in series is called

Ans.Battery

Class 6 Components of Food Important Question and Answers

 Class 6 Components of Food Important Question and Answers

One Word Answers
1.Night blindness of is caused by the deficiency of
Ans.Vitamin A
2.Weak bones and tooth decay is caused by the deficiency of
Ans.Calcium
3.Iodine Solution is used to test

Class 6 Science Food: Where Does It Come From Important Question Answers

CBSE Class 6 Science Food Where does it come from.. A.One Word Answers

Q1.Green plants prepare their own food, hence they are called as
Ans.Autotrophs
Q2.Pulses are rich source of

Class 8 Metals and Non Metals Short Answer Questions

Class 8 Metals and Non Metals Short Answer Questions 1. Name two soft metals which can be cut with a knife.
2. Which non-metal is essential for our life and all living beings inhale it during breathing?
3. Name two major non-metals which are present in fertilisers and enhance the growth of plants.
4. Which non-metal is used to disinfect water?
5. Why are bells made of metals?
6. Which liquid metal is used for making thermometers?
7.Some of the following statements are incorrect. Find the incorrect statements and correct them.
(a) The property of metals by virtue of which they can be drawn into wires is called ductility.
(b) Metals are good conductor of electricity but poor conductor of heat.
(c) Articles made of metals produce ringing sound when struck hard.
(d) Oxides of non-metals and metals are acidic in nature.
(e) A less reactive metal replaces a more reactive metal from its salt solution in water
8.Name the following
a)Non metal which is a good conductor of electricity
b)Non metal which is lustrous
C)Metal with highest melting point
d)Most reactive Metal
e)Which gas is released when metal reacts with acid
9.Name the non metal which is added to common salt
10.State whether the following statements are true or false :-
a. Metals form neutral oxides when react with oxyge n.
b. Solution of MgO in water turns red litmus paper to blue.
c. Rust is an oxide of iron.
d. Zinc reacts with water but copper reacts only wi th steam.
e. Zinc replaces copper from the copper sulphate so lution.
11.Fill in the blanks :-
a. Non metals are generally ______, so they break i nto pieces on hammering.
b. Sodium and ______ are soft enough to be cut with a knife.
c. Strings of musical instruments are made up of a ______ .
d. ______ is the only non metal which is a good con ductor of heat and electricity.
e. Metals oxides are ______ in nature because their solution in water turns red litmus blue.
12.Fill in the blanks :-
a. A pencil lead is made up of a non metal called _ _____ .
b. Non metal do not make a ______ sound when struck .
c. Non metals are ______ conductors of electricity.
d. Non metals are not good conductors of heat hence also called as ______ .
e. Bromine is the only non metal which is ______ at room temperature.

Class 8 Synthetic Fibres and Plastics Short Answer Questions

 Class 8 Synthetic Fibres and Plastics Short Answer Questions

1.Name the natural polymer and its units
2.What is the common name of artificial silk
3.Which fibre has stronger tensile strength than steel

Class 8 Microorganisms Friend And Foe Short Answer Questions

Class 8 Microorganisms Friend And Foe Short Answer Questions 
1.Unscramble the jumbled words underlined in the following statements.
(a) Cells of our body produce santiidobe to fight pathogens.

(b) curbossulite is an air-borne disease caused by a bacterium.

Acids Bases and Salts Important Question and Answers

Q1.Why alkalis like sodium hydroxide and potassium hyd roxide should not be left exposed to air?

Ans.Alkalis should not be left exposed to air be cause they are hygroscopic in nature and absorb moisture from atmosphere in which they g et dissolved.

Q2.Dry ammonia has no action on litmus paper but a sol ution of ammonia in water turns red litmus paper blue. Why is it so?

Biology Class 10 important questions

Q1.Which natural resources are called the “ biodiversity hot spots ”? How these hot spots maintain ecological balance ?
Q2.Explain with the help of labelled diagrams the development that takes place in each of the body parts of a Planaria where body is cut into three pieces. None this process and give an example of an organism in which a similar process can be observed.
Q3.List any four methods of contraception used b y humans. How does the use of three methods have a direct effect on the heath and prosperity of a family?
Q4.A. How does speciation take place?
B. Define the term GENE.
C. The gene for red hair is recessive to the gene for black hair. What will be the hair colour of a child if he inherits a gene for red colour from his mother and a gene for black hair from his father? Express with the help of flow chart
Q5.“Different species use different strategies to determine sex of a new born individual. It can be environmental cues or genetically determined”. Justify this statement giving reason/example
Q6.What are homologous organs? How do they provide evi dence in support of evolution?
Q7.Explain double fertilization in plants.
Q8.Name one organ analogous to the wing of the bird. W hy are they both analogous? Can you include the wing of bat also with them under the sa me category? Give reason.
Q9.Discuss in brief the various modes of reproduction used by single organisms.
Q10.DDT that was sprayed in minute amount on food plant s was detected in high concentration in man? How did it happen? Explain.
Q11.State three laws of Mendel.
Q12.Mention any four details that can be inferred about organisms from their fossils.
Q13.Energy transfer is said to be unidirectional where as biochemical transfer is said be cyclic. Why?
Q15.What are the advantages and disadvantages of self a nd cross pollination? Which of them is better and why?
Q16.How has the method of ‘artificial selection’ by hum ans helped in the evolution of different vegetables?
Q17.What is ten percent law? Explain with an example ho w energy flows through different trophic levels?

Class X Physics SA 2 Important Questions

Q1.When a c oncave mirror is placed facing the Sun, the Sun’s rays converge to a point 10 cm from the mirror. Now, if you place a 2 cm long candles flame 20 cm away on the principal axis of the mirror, where would you place a screen to obtain the image of the candle? What would see the size of the image? Draw a ray diagram to justify your answer.

Class X Chemistry SA 2 Important Questions

1.Name the product formed beside soap that is obtaine d during saponification process.
2.Define Mendeleev’s Periodic Law. Give two advantage s of Mendeleev’s Periodic Table.
3.Why was it necessary to change the basis of classif ication from atomic mass to atomic number. 4.(a) A compound X is formed by the reaction of carboxyli c acid having the molecular formula C 2 H 4 O 2 and alcohol (Y) in the presence of conc. H 2 SO 4 . The same carboxylic acid is obtained by the oxidation of alcohol (Y). Name the compounds X and Y. Give the chemical equation for the reaction.

DPS SA 2 Class 7 Sample papers

Download sample papers for Delhi Public School Class 7 SA 2 Examinations 2017

DPS SA 2 Class 8 Sample Papers 2017

Download Delhi Public School Class 8 SA 2 Sample papers 2017

CBSE Class 8 Sound Worksheet

1.What is noise pollution and how is it caused and write its four harmful effects

2.What is frequency , amplitude.

3.Draw waves with same frequency and different amplitude, and with same amplitude and different frequency

CBSE Class X Social Science SA 2 Sample papers 2017

Download Sample paper for Class 10 SA 2 Social Science 2017 Examinations

Class 10 Maths SA 2 Sample papers 2017

Download Maths SA 2 Sample papers for Class 10 Examinations 2017

Class 10 SA 2 English Communicative Sample papers 2017

Download CBSE Class 10 English Communicative Sample papers for S A 2 2017

DPS SA 2 Sample Papers Class VI

Hellen Keller:The story of my life SA 2 Question Answers

SA 2  Important Questions of Helen Keller:The story of my life

CBSE Class X Helen Keller Important Question


1.How did Helen pass her time when she was not reading?

Ans.Helen's amusements, when she is not reading, are not very different from those of other young women
 loves to be outside and to swim
 enjoys canoeing, especially on moonlit nights, and her favorite pastime is sailing
 speaks of her lo ve for her "tree friends."
 feels so close to them that she imagines she can hear their sap flow and see the sunshine on their leaves

Class 9 Diversity in living organisms Sample Paper Question Answers


 Class 9 Diversity in living organisms Sample Paper Question Answers


1.(i) State reasons why Echidna and platypus lay eggs but are considered as mammals.

Ans.They have mammary glands for the production of milk to nourish their young ones.

(ii) Forelimbs of birds are modified

Ans.To reduce body weight for flight.

Sound CBSE Class 8 Important Question and Answers

Q.1 How does a sound making object differ from one that is silent?
Answer: Sound making object can vibrate easily.                    

Q.2 How does sound from a sound producing body travel through air to reach our ears?
Answer: Sound from a sound producing body travel through air to reach our ears by making regular compression and
rarefaction.

Q.3  Why are the voices of men, Women and children different?

Answer: The voices of men, women and children differ from each other due to the following factors:

(i) The pitch is one of the most essential factors to determine the voice of the individual. For example, men have lower-pitched voices while women have higher-pitched voices.
(ii) Second factor which brings in the difference in the voices is the length and the thickness of vocal cords.

Q.4  Why a sound cannot be heard on the moon?
Answer: A sound cannot be heard on the moon due to absence of medium air

Q.5  How do astronauts talk to one another on the surface of moon and Why?
Answer:  Astronauts communicate with the help of radio waves on moon because these waves do not need a medium to travel

Q.6  If you want to hear a train approaching from far away, why is it more convenient to put the ear to the track?
Answer: This is because sound can travel through railway track (solid ) faster than through air.


Q.7  State one observation from everyday life which shows that sound travels much more slowly than light?Answer: We hear thunder after lightining.

Q.8  What is the scientific name for the following? The number of vibrations made per second.
Answer: Frequency

Q.9   Why do we not hear the screams of a bat?
Answer:  This is because the screams are ultra sonic(above 20,000 hertz) which human ear cannot hear.

Q.10  Which of the following frequency of sound can be heard by a dog but not by a man? (a) 50,000 hertz (b)   15,000 hertz 
Answer:  A sound of frequency 50,000 hertz can be heard by a dog but not by a man

Q.11 Explain how, noise pollution {or excessive loud noise} is harmful to human beings.
Answer: Noise pollution can lead to a number of health-related problems. Some of them are as follows:


(i) Hearing loss  (ii) inability to sleep    (iii) Hypertension (iv) Severe headache (v) Stress

Q.12  State the various measures which can be taken to control {or reduce} noise pollution in our surroundings.
Answer: Noise pollution can be reduced by using silencers in vehicles, industrial machines, and home appliances reducing use of vehicle horns, running TV, radio and music systems at low volumes. Planting of trees along roads and buildings also help to reduce noise pollution.

Q.13 Give two causes of noise pollution from the homes.
Answer: . In the home noise pollution is caused by television radio and  music systems at high volume, some kitchen appliances, desert coolers, air conditioners etc.

Q.14   Sound of different pitch can be produced using a flute. Explain, how?  
Answer: If we blow a flute, the air column vibrates and produces sound. Flute contains small air columns, when air is bowed through the mouth piece the air columns start vibrating which produces sound.

Q.15.How does Sound produced by humans?
Answer:  In humans sound is produced by the vioce box or larynx. It is the upper part of the wind pipe. Two vocal cords are stretched across the voice box leaving a narrow slit. When the lungs force air through the slit, it vibrates and produces sound.

Q. 16. How Jal Tarang produces sound?
Answer: In Jal-tarang musical instrument the cup containing minimum water produces the sound of lowest frequency or lowest pitch. As the amount of water in the cup goes on increasing, the frequency (or the pitch) of the sound produced also goes on increasing.

Q. 17. If 125 oscillations are produced in 5 seconds, what is the frequency in hertz?
Answer: in 5 seconds 125 oscillations are produced
So, in 51 seconds 125/5 = 25 oscillations are produced  Hence, the frequency = 25Hz

Q. 18. What is the frequency of a vibrating body whose time-period is 0.05 second?              
Answer: f = 1/t = 1/0.05 = 100/5 = 20HZ

Q. 18. State true or false
(i) Sound can be produced by beating an object irrespective of whether there are vibrations or not.
(ii)The sound of a tabla normally has a lower pitch than the sound of a violin.
(ii)A short flute will produce sound of lower pitch than a long flute.


Answer:
(i) –False [Sound is produced from a vibrating object.]
(ii) -True [The sound of a tabla normally has a lower pitch than the sound of a violin.]
(iii) –True[A short flute will produce sound of lower pitch than a long flute.]

Q.19. Give reasons Why Trees planted along the roads reduce noise?
Answer: Trees are planted along the roads and around buildings so that it could cut off sound vibrations produced from vehicles speakers etc. by absorbing them, hence leading in prevention of Noise pollution.

Q.20. what are transverse and longitudinal waves?
Answer: Longitudinal waves: A wave in which the particles of the medium vibrate back and forth in the same direction in which the wave is moving is called longitudinal wave. Example: sound waves.
Transverse waves: A wave in which the particles of the medium vibrate at right angles to the direction, in which the wave is moving, is called transverse wave. Example: Light waves.


Q.21. Explain how bats use ultrasounds to catch a prey ?

Ans: Bats search out prey and fly in dark night by emitting and detecting  reflections of ultrasonic waves. The high pitched ultrasonic squeaks of the bat are reflected from the obstacles or prey and returned to bat’s ear. The nature of reflection tells the bat where the obstacle or prey is and what it is like.

Q.22. Explain how moths of certain families are able to escape capture from a bat ?

Ans: Moths of certain families have very sensitive hearing equipment. These moths can hear the high frequency squeaks of the bat and know where a bat is flying nearby and are able to escape capture.

Q. 23.How does the ear drum of human ear vibrate ?
When a compression of the medium reaches the eardrum the pressure on the outside of the membrane increases and forces the eardrum inward. Similarly the eardrum moves outward when a rarefaction reaches it. In this way the eardrum vibrates.

Q. What is the role of hammer bone, anvil bone, stirrup bone and cochlea of human ear in hearing a sound 
Ans: The vibrations due to the ear drum is amplified several times by three bones in the middle ear. The pressure variations in the inner ear turned in to electrical signals by the cochlea.

Q.24. How does the stethoscope help the doctors in listening to the sound of the patients heart beat?

Ans. In a stethoscope, the sound produced within the body of a patient is picked up by a sensitive diaphragm and then reaches the doctor's ear by multiple reflections. Q.3. Explain how defects in a metal block can be detected using ultrasound. Ans. To detect minor cracks or flaws in metal block, ultrasonic waves are allowed to pass through metal blocks and detectors are used to detect the transmitted waves. If there is a crack in metal block, these waves get reflected back

Q.25. How is ultrasound used for cleaning?

Ans. The object to be cleaned is put in a tank fitted with ultrasonic vibrator. The tank is filled with cleaning solution. As the ultrasonic vibrator is switched on, high frequency vibrations are set up and the dust, grease and dust particles get detached and the object gets thoroughly cleaned


26.What is the difference between noise and music? Can music become noise sometimes?
Ans.The unpleasant sound is called noise. Whereas pl easant sound is called music. Noise can produce so many health hazards, whereas noise m usic brings about soothing effect. Yes, music can become a noise sometimes when the mu sical instruments produce very high volume sounds.

27.On what factors pitch and loudness of the sound depends
Ans.The pitch of the sound depends on frequency,
and the loudness of the sound depends on the amplitude.




STARS AND THE SOLAR SYSTEM CBSE Class 8 Important Question Solutions


Short Answers
Q.1.Name the planet appears I the northern sky before sun rise?

Ans: Venus brightest of all planets
Q.2. Name the planet which has 28 moons?
Ans: Jupiter manly consist of hydrogen and helium gases
Q.3. In which direction stars move except Polar star?

Why Do We Fall ILL Important Questions Worksheet

CBSE Class 9 Why Do We Fall ILL Important Questions Worksheet


1.In a school assembly, the students were asked to we ar full sleeves shirts, full pants and socks pulled till knees, use mosquitoes repellants cream during day time.
(i) Name the disease, about which preventive instru ction are given in the assembly.
(ii) Name the vector of this disease.
(iii) Give two preventive environmental measures.
(iv) Which two values were given in assembly relate d to society?

CBSE Class 7 Triangle and its properties Important Question Worksheet

CBSE Class 7 Triangle and its properties Important Question Worksheet

1. The top of a broken tree touches the ground at a distance of 12 m from its base. If the tree is broken at a height of 5 m from the ground then the actual height of the tree is

2.Two trees 7 m and 4 m high stand upright on a ground. If their bases (roots) are 4 m apart, then the distance between their tops is

CBSE Class 7 Comparing Quantities Important Questions Worksheet

1.If Rahul pays an interest of ` 1500 for 4 years on a sum of ` 2500, find the rate of interest per annum(p.a.)

2.Gayatri’s income is ` 1,60,000 per year . She pays 15% of this as house rent and 10% of the remainder on her child’s education. The money left with her is

3.Convert into decimal i)27% ii)2.6% ii)0.9%

CLASS X Chemistry:Carbon and Its compounds Worksheet

1 Name the process of converting vegetable oil to vegetable ghee
2. What are isomers? “Isomers of the first three members of alkane series are not possible”. Give reason to justify this statement and draw structures of two isomers of butane, three isomers of pentane

CBSE Class 7 Reproduction in Plants NCERT Solutions

1. Fill in the blanks:
(a) Production of new individual from the vegetative parts of parent is called vegetative propagation .
(b) A flower may have either male or female reproductive parts. Such flower is called unisexual flowers .

CLass 7 Waste Water Story NCERT Solutions

1. Fill in the blanks:
(a) Cleaning of water is process of removing contaminants .
(b) Wastewater released by houses is called sewage .
(c) Dried dung is used as manure.
(d) Drains get blocked by plastic and sludge .

Class 7 Science Transportation In Plants and Animals NCERT Solutions

NCERT Solutions for Transportation in Plants and Animals

Ans.2) (i) (b) (ii) (d) (iii) (a) (iv) (c)

CBSE Class 6 Algebric Expressions Worksheet

1.Write the equation for the following expressions
(a) x is multiplied by itself and then added to the product of x and y .
(b) Three times of p and two times of q are multiplied and then subtracted from r .
(c) Product of p , twice of q and thrice of r .
(d) Sum of the products of a and b , b and c and c and a.
(e) Perimeter of an equilateral triangle of side x.

Carbon and its compounds Important Questions and Answers

CBSE Class 10 Important Question and Answers of Carbon and Its compounds Sample paper 2017


1.A salt X is formed and a gas is evolved when ethanoi c acid reacts with sodium hydrogen carbonate. Name the salt X and the gas evolved. D escribe an activity and draw the diagram of the apparatus to prove that the evo lved gas is the one which you have named. Also, write chemical equation of the reaction involved.

CBSE Class 9 Science SA 2 Sample paper 2017

1. Name the Indian philosopher who proposed the theory of matter.

2. What is Dalton?

3. Define 1 watt of power.

4. Will advanced organisms be the same as complex orga nisms? Why?

5. Why are sound waves called mechanical waves?

6. List any three human activities which would lead to an increase in the carbon dioxide content of air.

Class 9 Science Sample paper 2017

1. Define atomicity.

2. What is an ion?

3. Define average power.

CBSE Class IX Science Sample paper SA 2 2017

1. What are polyatomic ions?

2. What is meant by the term chemical formula?

3. State the law of conservation of energy.

4. How would you choose between two characteristics to be used for developing a hierarchy in classification?

CBSE Class 9 Science SA 2 Sample paper 2017

1. Give one word for the following:

(i) Positively charged ion

(ii) A group of atoms carrying a charge

CBSE Class 9 Science Sample Paper 2017

1. Give an example of a tri-atomic molecule of an elem ent.

2. Valency of an element X is 3. Write the chemical fo rmula of its oxide.

3. What is negative work.

4. Why do we keep both snake and turtle in the same cl ass?

5. Why is sound wave called a longitudinal wave?

Science Sample Paper Class X Sample paper 2017




3. What are the values of (i) Angle of incidence and ( ii) Angle of reflection for normal incidence on a plane surface?

CBSE Class X Science Sample paper SA 2 2017

1. What is meant by water table?

2. Name the second member of alkynes family Give its s tructure?

3. What is the focal length of a lens, whose power is given as +2.0 D?

4. Why does it take some time to see objects in dim li ght when you enter the room from bright sunlight outside?

Class X Science SA 2 Sampe Paper




2. Name any two biodegradable pollutants.

3. Define soaps?

4. Why is water necessary for living organisms?

CBSE Class X Science SA 2 Sample paper 2017


CBSE Sample Paper-02
SUMMATIVE ASSESSMENT –II
SCIENCE (Theory)
Class – X

1. What is acid rain?

2. Name the product formed beside soap that is obtained during saponification process.

3. Are the laws of reflection applicable to plane surf aces also valid for curved surfaces?

CBSE Class 10 Science Sample Paper 2017


CBSE Sample Paper 2017
SUMMATIVE ASSESSMENT –II
SCIENCE (Theory)
Class – X







1 Name the process of converting vegetable oil to vegetable ghee.

2 List two secondary sexual characters of males that are different from that of females.

3 Write the main function of Ozone in the upper atmosphere

Mensuration Class 7 Worksheet

1.A wire is bent to form a square of side 22 cm. If the wire is rebent to form a circle, its radius is

Ratio and Proportion Class 6 Important Questions Worksheet

Practice exercise for Ratio and Proportion Class 6 Maths CBSE

Here is a worksheet for Class 6 MAths:Ratio and Proportion

1.Divide Rs 60 in the ratio 1 : 2 between Kirti and Kamal.
2.Length and breadth of a rectangular field are 50 m and 15 m respectively. Find the ratio of the length to the perimeter of the field

Atoms and Molecules Class 9 Worksheet

1.Give an example of a tri-atomic molecule of an elem ent.
2.Give one word for the following:
(i) Positively charged ion
(ii) A group of atoms carrying a charge
3.What are polyatomic ions? Give examples
4. State the Postulates of Dalton Theory?
5.What is the molecular formula for
i)Calcium hydroxide
ii)Magnesium Phosphate
iii)zinc Nitrate
iv)Aluminium oxide
v)Sodium Carbonate
vi)Aluminium chloride
5). 6.2.42g of copper gave 3.025 g of a black oxide of copper, 6. 4 9 g of a black oxide, on reduction with hydrogen, gave 5.192g of copper. Sho w that these figures are in accordance with law of constant proportion?

7.alculate the number of aluminium ions present in 0.051 g of aluminium oxide. ( Hint: The mass of an ion is the same as that of an atom o f the same element. Atomic mass of Al = 27 u)

8.What is the mass of:
(a) 0.2 mole of oxygen atoms?
(b) 0.5 mole of water molecules?
9.ive the names of the elements present in the f ollowing compounds.
(a) Quick lime
(b) Hydrogen bromide
(c) Baking powder
(d) Potassium sulphate.

10. Which has more number of atoms, 100 grams of so dium or 100 grams of iron (given, atomic mass of Na = 23 u, Fe = 56 u)?

11.alculate the formula unit masses of ZnO, Na2 O, K 2 CO 3 , given atomic masses of Zn = 65 u, Na = 23 u, K = 39 u, C = 12 u, and O = 16 u.
12.State the differences betwee n an atom or a molecule.
13.Calculate the number of moles for the following:
a) 52 g of He
b) 17 g of water

Money and Credit CBSE Class 10 Important Question and Answers

1. Which is the main source of credit for urban househ olds?
Ans.Banks and Cooperatives

2. Name the agency from whom Arun took loan to meet he r expenses
Ans.Bank

Gulliver's Travels CBSE Class 9 SA 2 Important Question and Answers

Gulliver Travels Class 9 SA 2 Important Questions and Answers
Gulliver Travel's Study Material

Q1.A. Describe the notion of money which is prevalent in Gul liver’s country and which he explained to the master of Houyhnhnms

Ans. Gulliver told the master that when a man acquires a considerable amount of money, he can purchase the finest clothes, the best house, larg e areas of land, the most costly food and drinks. He can also have the choice of the most beauti ful woman. Besides, the rich men enjoyed the fruits of the poor man’s labour. During his conversation, the most amazing fact which Gulliver revealed to the master was that the n umber of poor people were far greater than the rich ones. The poor people were mostly beggars. They lived a hard life. Such a vast difference between the rich and the poor people was ca used by the power of money. Obviously, rich had made the poor people their slaves. This fact was really shocking for the master of Houyhnhnms.

Class 8 Mensuration Important Questions Worksheet

1.In a building there are 4 cylindrical pillars. T he radius of each pillar is 21 cm and height is 5 m. Find the curved surface area of four pillars.

Class 10 Probability Important Questions Worksheet

CBSE Class 10 Probability Important Questions Worksheet

1.A die is thrown once. Find the probability of getti ng:
(i) a prime number
(ii) a number lying between 2 and 6
(iii) an odd number

Area Related to Circles Class 10 Important Questions Worksheet

Important Questions Worksheet of Area Related to Circles

1.The radii of two circles are 19cm and 9cm respectiv ely. Find the radius of the circle which has its circumference equal to the sum of the circumference of the two circles

2.An umbrella has 8 ribs, which are equally spaced, a ssuming umbrella to be a flat circle of radius 45 cm. Find the area between two c onsecutive ribs of the umbrella.

Class 10 Coordinate Geometry Important Questions

Class 10 Coordinate Geometry Sample Paper Questions

Coordinate Geometry WorkSheet

Download CBSE Worksheet for Coordinate Geometry Class X


1.If A (4, 2), B (7, 6) and C (1, 4) are the vertices of a ABC ∆ and AD is in median, prove that the median AD divides AABC into two triangles of equal areas.


The Nationalist Movement in Indo China Class 10 Notes

Important Question and Answers History Class 10:The Nationalist movement in Indo china


1. Which one of the European trading company founded t he Port of FAIFO
Anst is the agency that develops standards for g oods and services.

2. Name the countries which comprise indo china?
Ans. Laos, Cambodia and Vietnam

How do Organisms Reproduce Class 10 Ncert Solutions

NCERT Solutions How do Organisms Reproduce
1.What is the importance of DNA copying in reprod uction?
Ans.DNA contains information for the inheritance of features from parents to next generation. DNA presents in nucleus of cells are th e information source for making protein. If information is different, different pro tein will be made that lead to altered body design.

2.Why is variation beneficial to the species but not necessarily for the individual?
Ans.Variations are useful for the survival of speci es in changed environment situations. If a population of reproducing organism were suited to a particular niche and if the niche is drastically altered the population could b e wiped out. However, some variations are present some species will survive. T hus, variation is useful to species but not the individual.

CBSE Class 10 Snake Summary and Study Material

Setting of the Poem Snake

This poem is set in the poet’s backyard, where there is a water-trough. When the poet goes to the trough to fill a pitcher with water for his own use, he encounters a snake which has come to the trough before him. The entire poem revolves around this very encounter.

Summary of Snake by D.H.Lawrence

The poem consists of 19 stanzas of variable lengths. The entire poem consists of 75 lines in total.
1st stanza:

Class 10 English Virtually True Summary

The story starts with a boy named Michael who reads an article in the newspaper about a "Miracle Recovery." A boy whose condition was critical but stable had been recovered from coma. Michael recollects that the boy who was mentioned in the newspaper was in fact Sebastian Shultz who he had met weeks ago while playing. This all started in the Computer Fair, when Michael's father who was Nutty about computers, bought him a new computer preloaded with games. When he plays the game ‘Wild West’, he becomes a Sheriff and is challenged by "Black eyed Jed" to a duel. He meets a Second Sheriff whom he was asked to go with. Unfortunately, the Second Sheriff gets shot by the villains and the game ends. Later on, he gets a printout which read "I 'm Sebastian Shultz try playing Dragon Quest".

Political Parties CBSE Class 10 Important Questions

1. What is symbol of Samajwadi Party?
Ans.Cycle

2. Which is the oldest recognized political party of I ndia?
Ans.Indian National congress

3. How many political parties are recognized with the Election Commission?
Ans.750

Rime of Ancient Mariner CBSE Class 10 | Rime of Ancient Mariner Important notes

Three guys are on the way to a wedding celebration when an old sailor (the Mariner) stops one of them at the door (we'll call him the Wedding Guest). Using his hypnotic eyes to hold the attention of the Wedding Guest, he starts telling a story about a disastrous journey he took. The Wedding Guest really wants to go party, but he can't pry himself away from this grizzled old mariner. The Mariner begins his story. They left port, and the ship sailed down near Antarctica to get away from a bad storm, but then they get caught in a dangerous, foggy ice field. An albatross shows up to steer them through the fog and provide good winds, but then the Mariner decides to shoot it. Oops.

Ozymandias CBSE Class 10 Summar | Ozymandias Important notes

I met a traveller from an antique land
Who said...

    The poem begins immediately with an encounter between the speaker and a traveler that comes from an "antique land."
    We're not sure about this traveler. He could be a native of this "antique" land, or just a tourist returning from his latest trip.

Market Around Us CBSE Class 7 Important Notes

Important notes of Civics Class 7

Market around us important notes.

Weekly market;
1.It is held on a specific day of the week
2.They do not have permanent shops
3.Traders set up shops for the day and close them in the evening
4.There are thousands of weekly markets in India

Diversity in Living Organisms Class 9 Solutions

Important question and answers of diversity in living organisms Class 9

CBSE Class 9 Science Biology Diversity in living organisms question and answers

1.In what respects are lichens unusual plants?
Ans. lichen is a close partnership between an alga and a fungus. The algal cells grow in the fungal mycelium. Alga make food by photosynt hesis. The fungus provides shelter and protection to the alga. Thus, both the alga and the fungus benefit. This kind of association is called a symbiotic asso ciation.

2.Na me two coelenterates with diagrams. How do porifera n animals differ from coelenterate animals?
Ans.Examples of coelenterates. Poriferans are the simplest multicellular and branched. The cells are loosely held together and do not form tissue Coelenterates have one continuous central cavity called coelentron.

Globalisation and indian Economy CBSE Class 10 Solutions

 Globalisation and Indian Economy CBSE Class 10 Important Question and Answers

Solution for Social Science Class 10 CBSE Globalisation


1.In what three ways has liberalization of trade and investment policies helped the globalisation process?
Ans.A. With liberalization of trade, industrialists are al lowed to make decisions freely about what they wish to import and export.
B. Goods now be imported and exported easily.
C. Companies can set their manufacturing units any oth er country of the world.
D. The process of foreign trade and investment has bee n increased by the MNCs.
E. Domestic companies are free to compete with produce rs around the world.

Our Environment CBSE Class 10 Important Question and Answers

1.Why is there a need to b an the use of poly then e bags?
Ans.Polythene bags are non- biodegradable, the y are not decomposed by micro- organisms hence, cause land pollution.

2.What are the two functions of ecosystem?
Ans.Interactions of any ecosystem refers to it s functions these interactions are-
(A) Biogeochemical cycles- The cyclic transfers between the living and non- living components.
(B) Flow of energy- in a food chain, through various st eps of eating and being eaten food energy flow from one tropic level t o another.

Rearranging the Jumbled Words Exercise

1.Rearrange the following jumbled words to form meaningf ul sentences.
(a) through the atmosphere /of the sun /the /are scatt ered as /rays /they / travel
(b) the sun /overhead /is /when /rays /the verticall y /travel
(c) yellow colour /scattered /the /is /more so /appears /overhead /yellow / the sun

Three Men in a Boat CBSE Class 9 Important Question and Answers

 Three Men in a Boat CBSE Class 9 Important Question and Answers 
SA 2

Q1. Justify the title ‘Three Men in a Boat’.
Ans. The title is apt for the novel ‘Three Men in a Boat’ . The entire theme of the novel, “Three Men in a Boat” is based on the river journey. This jour ney is undertaken by the narrator and his two friends, George and Harris. They make the ir journey on a boat in River Thames. Their journey is for two weeks and almost all the important places located on the banks of the river Thames is visited. During the ir journey, they cook and sleep in their boat. We can say that for at least a fortnight, the boat became their home. They have absolutely no complaint with regard to the homely c omforts which they may not get in the boat. Their journey starts from Kingston and ends at Oxford. During their journey, the narrator and his friends enjoy every momen t in the river. During their stay at night, they visit the local places and enjoy life. Therefore, it can be said that narrator has selected appropriate title for the present novel, “Three Men in a Boat”.

AdSense

Download CLASS 10th CBSE Sample papers 2019

CBSE Sample Papers for Class 10 Science 2019 Solved Science Sample Question Paper 2019 Set 1 Solved Science Sample Question Paper 2019 ...