Sunday, January 27, 2013


1. An old man and a scientist were talking about a deserted house. The old man was sure that it was haunted by ghosts, but the scientist discarded the view saying no one had ever seen a ghost. The old man was annoyed and challenged the scientist about existence of atoms, sub-atomic particles which also could not be seen.
· Name the three sub-atomic particles and their discoverers.
· Whose viewpoint do you support and why?
2. An activity was conducted in a classroom where students held placards with symbols and valency of the elements separately. Each student held two placards, one with the symbol in the right hand and other with the valency in the left hand.
· Which placards will be required for formation of sodium chloride ( both symbol
as well as valency).
· Which qualities are required in the student to perform such a group activity?
3. Two class IX students, Kaveri and Nalin, were asked to take 5.3 g of sodium carbonate and 6g of ethanoic acid to make 2.2g of carbon dioxide, 0.9g of water and 8.2 g of sodium ethanoate. Kaveri followed the instructions but Nalin took the chemicals without measuring their amounts.
· Whose activity do you think will be in agreement with the law of ``Conservation of mass''?
· State the law of ``Conservation of mass''.
· Whose method do you like and why?
4. Raghu and Vansh were performing an activity related to conservation of mass in chemistry lab of their school. They mixed a solution of barium chloride and sodium sulphate. Raghu suggested that as they already knew the amount of both compounds taken by them, they need not to measure the amount of final solution. On the contrary, Vansh insisted to measure the amount of final solution, which had barium sulphate and sodium chloride. Atomic mass of ions: Ba 2+ = 137 units, Cl - = 35.5
        units, Na + = 23 units, S2 - = 32units, O2 - = 16 units.
Determine the molecular mass of
a) Barium chloride
b) Barium sulphate
c) Sodium sulphate
d) Sodium chloride
· Comment on Vansh's Insistence to complete the activity.
5. Beenu was quite confused when she was taught mole concept in the class. Same evening she went to the market with her mother to buy fruits. Her mother bought one dozen apples, one dozen oranges and one dozen (one dozen=12 piece.) banana, fruits-seller gave the fruit according to their mass in kg. on observing their respective masses, beenu understood the mole concept instantly.
· Can you explain what made Beenu understand mole-concept?
· What is Avogadro's constant.
6. Ayush is not keeping happy and is unable to focus on studies. His friend Udghosh observed the same and inquired Ayush. Udghosh was told by Ayush that his younger brother is not keeping good health. His neck has swollen. The fact that Ayush's family was not including iodized salt in their diet came to light. Udghosh immediately suggested certain measures and insisted that Ayush's brother must
see the doctor without any delay.
· What values are displayed by Udghosh?
· What can be possibly the disease from which Ayush's brother is suffering?
         · Name the element whose isotope is used in the treatment for the disease.


CBSE-CH: Floatation GRAVITATION]                             
Q1.While passing nearby a pond, some students saw a drowning man screaming forhelp. They alerted another passerby, who immediately threw an inflated rubber tube in the pond. The man was saved.· Why the passerby did use inflated rubber tube to save the  drowning man? ·Write the principle involved here.· Which qualities shown by the students and the passerby do you identify that helped in saving the drowning man?

Q2.You received  an e-mail from  a friend living in  a coastal town. He shared an experience with you that recently, while swimming on the coastline of the sea in common swimming attire, he thought of going deeper inside the sea. He was asked to abstain from delving deeper into the sea by the rescue personnel. Respond  to the following questions using the information provided above.Why the rescue personnel asked your friend not to swim deeper inside the sea? · What values were exhibited by the rescue personnel?

Q3.Nitya is visiting her relativesin Bhopal. One day her aunt expressed unhappiness with the milk supplied by the milkman. She complained of adulterated milk. Nitya asked her to buy an instrument to check the purity of milk. Next day, the supplied milk was tested and found water being mixed in the milk. Nitya's aunt informed all her neighbors about the instrument.· What values are shown by Nitya, her aunt and the milkman respectively? · Identify the instrument and the principle on which it is based?

Q4.During the summer vacations, Gaurav visited his native village. He observed that for washing clothes, villagers used the water from the well. Out of curiosity he drew water from the well and observed that the bucket of water appeared to be heavier asit came out of the water.· Name the principle used in the above passage.· Why bucket appears to be heavier in air? · Which values are reflected in Gaurav's  behavior.


Q.1An educational tour to Mumbai was organized. While visiting the seashore,Vyom,one of the students observed that direction of wind changed during the day time and night. He asked his science teacher who accompanied them, the possible reasons for his observations.· What possible reasons, teacher gave to the student.· Name two other factors which influence winds.· Comment on the values shown by the student.

Q2.Due to heavy rains and speedy winds a tree broke and fell on the road. Two persons from local shops came and begin to remove that broken part of the tree,but in vain as the log was too heavy. A passerby came to their help with a few solid heavy sticks. Consequently, the heavy log was put aside and the commutationon the road began as usual.· Comment upon the value(s) displayed by the passerby?· Name the energy stored when the heavy log of the tree waslifted to some height?

Q3.Mr. Shah's family was worried about heavy electricity bills to be paid. Their neighbour Mr. Sen suggested some easy and effective steps to reduce the same. Next month's bill came as a relief to Mr. Shah, as the consumption of electricity had reduced by 50 units and so had the bill.· What is the unit of ``Power''.· What is it a measure of energy or power? · Write any three steps that you think Mr. Sen might have suggested to Mr. Shah.

Q4.Amit and Nitin were observing a building having two different staircase. One slanting and other vertically spiral. Amit was of the opinion that a person using slanting staircase will be  doing more work  against  gravity but Nitin thought otherwise. They started quarrelling. Asif, their friend, explained and gave entirely different view and pacified them.· What according to you was the explanation given by Asif? · What appreciable values do you see in the Asif?

Q5.Four tubelights of 60 watt each, three fans of 60 watt each and a geyser of 500 watt operates for eight hours everyday in a household. The electricity bill made Mr. Abhinav worried. He discovered the usage of geyser, unnecessary longer. He conveyed to the family membersthat energy guzzling appliances and gadgets ought to be wisely used according to the need.(hint:- 1watt = 0.001 kilowatt = 1 unit)· Calculate the total electrical units of energy consumed if the month is September.· Comment upon the values demonstrated by Mr. Abhinav.· Convert 1 kilowatt hour into joules.

Q6.Aditya and his friends were playing with a catapult (gulel) in his garden. Several mangoes were dislodged and fell with the help of catapult. One of his friend was aiming the catapult on a bird. Aditya prevented him from doing so.· Name the energy possessed by the stretched string of the catapult· What will happen if the stone isthrown without stretching the string of a catapult? ·Why Aditya did prevent his friend from aiming at the bird?Which quality is highlighted inAditya's behavior?

Q7.Raghu lives in a village and his school is 8 km away from his home. His father suggests buying a motor cycle to go to school. Raghu opposesthe idea and opt fora bicycle instead.. Write the energy transformation taking place while Raghu rides his bicycle.· If Raghu paddles the bicycle with a speed of 8 Km/hr and he wantsto Reach 

10 minutes before the school commences. Whatshould be the duration before which he must leave his house?· Justify the stand taken by Raghu in your own words.

Chapter SOUND
Q1.In a hot summer afternoon a man was shouting through a megaphone. He was'zip-repairer'. As Arshi was preparing for her examination, she got disturbed. She inquired her father about the instrument being used by the 'zip-repairer'. The fathertold her that it was a megaphone also known as 'loud hailer'.· State the principle on which the megaphone works.· Why did  Arshi get disturbed?· Why megaphones should not be used in residential area?

Q2.Kunal andAbhimanyu were waiting to go across a railway crossing. Kunal jumped over the barrier and curiously put his ear on the railway track.Abhimanyu opposed Kunal and pulled him away from the railway track.· Why did Kunal put his ear on the railway track? · Can sound travel faster through, (i). Copper  (ii). Water. Why did Abhimanyu pulled Kunal away from the railway track?

Q3.Ashish had a pain in his ear as he pricked it with a pin. The doctor advised we should take proper care of our ears and protect them from damage.· Why we must not prick with hard and pointed things inside our ears? · What is the function of ear?

Q4.Reena's grandmother took her mother to a doctor ass he was four months pregnant for ultra-sonography. But she showed her interest in determining whether the child is a boy or a girl. The doctor was annoyed and refused to disclose the gender ofthe child.· What is ultra-sonography?· On what principle does it work?· Why do you think the doctor refused to determine the gender of the child? · Why is ultrasonography important?

Q.5Harsha was watching a program based on ships on television. She saw a device attached to a ship through which the men on the ship located the enemy submarines and sent the message to the headquarters.· Name the device fitted in the ship.· Write the full form of the device.· On which principle does the device work? · Write other uses of the device.

Saturday, January 26, 2013

NCERT/CBSE -7th Science Ch–Waste Water Story Solved Questions

Q. Explain the process of waste water treatment?

Ans: The wastewater is treated through physical, chemical, and biological processes to remove the physical, chemical and biological contaminants.
Physical - separates the large waste
Biological- Adding of microorganisms to digest waste and produce oxygen in water
Chemical- Chlorine and other chemicals are added into the water to finally purify it.

Q. what is sewage?

Ans: Wastewater is generated during various activities in homes, industries, hospitals, offices, and laundry services etc. This waste water is called sewage.

Q. Explain the vercomposting toilet ?           

Ans: Vermicomposting toilets are those which do not use water and are very environment friendly. They can be utilized in areas where water is a scarcity and can also be used in forests and other areas where sewage lines have not been built. This process uses worms for decomposition of waste. The waste is degraded in a container.
Q. what are the process of waste water management of rain water ?

Ans: The rain water that runs down after washing off the rooftops, roads etc. is dirty and carries harmful pollutants. The waste water containing solid and liquid pollutants is known as sewage. The process of removing the contaminants from sewage water is done through various stages. This entire process is known as the sewage water treatment process.

Q. What is Eutrophication?

Ans: Eutrophication is the presence of excess nutrients in water bodies. Release of nutrient rich sewage and industrial effluents lead to introduction of nutrients such as nitrogen and phosphorus in the water body. This leads to the increase in temperature called algal blooms.

Q. Each tree can make its own manure. How?

Ans: Plants shade their leaves that are biodegrable and converted into compost when get covered under soil. Thus each tree can make its own manure.

Q. Fill in the blanks:

(a) Cleaning of water is a process of removing  pollutants.
(b) Wastewater released by houses is called   sewage.
(c) Dried sludge is used as manure.
(d) Drains get blocked solid and liqidby tealeaves, solid food remains, soft toys, cotton, and  sanitary towels .
CBSE 7th Waste Water Story management Solved Test Paper  Click here
CBSE 7th Waste Water Story management Solved questions    Click here        
Assignment Chapter –Waste Water Story                                   Click Here

Friday, January 18, 2013

CBSE_NCERT- 10th : Chapter wise test-Periodic Classification of elements

2 Marks Questions [2 x 5 = 10 ]

1. An element has electronic configuration 2, 8, 3. What is the atomic number of this element? To which (i) group and (ii) period this element belong?

2. State the positions of (i) isotopes of the same element and (ii) hydrogen in the Modern Periodic Table.

3. How does the tendency to gain electrons change as we go down the 16th group of periodic table? Why?

4. Give reasons for the following :  (a) Lithium atom is smaller than sodium atom. (b) Chlorine (atomicnumber 17) is more electronegative than sulphur (atomic number 16)

5. (a) State the Modern Periodic Law.  (b) Name the element which has twice as many electrons in its second shell as in its first shell. Write its electronic configuration also.

3 Marks Questions [ 3 x 5 = 15 ]

1. An element X belongs to group 17 and third period of the periodic table.  (a) Write electronicconfiguration of the element. What is its valency?   (b) Predict its nature, whether it is a metal or non-metal. (c) Give the formula of the compound formed when it combines with an element Y having valency three.

2. Three elements A, B and C have atomic number 7, 8 and 9 respectively.  (a) What would be their positions in the Modern Periodic Table (Mention group and period both)? (b) Arrange A, B and C in the decreasing order of their size. (c) Which one of the three elements is most reactive and why?

3. (a) The elements of the second period along with their atomic number in parenthesis are given below : B (5), Be (4), O (8), N (7), Li (3), C (6), F (9)  (i) Arrange them in the same order as they are in the periodic table.   (ii) Which element has the (i) largest (ii) smallest atom? (b) Why does the atomic radius change as we move from left to right in a period?

4. (a) How is the valency of an element determined from its position in the periodic table? (b) Magnesium has atomic number 12. To which (i) group (ii) period of the periodic table does it belong? (c) The valency of all the elements in a group is same. Why?

5. A part of the periodic table has been shown below :

Group →
Period ↓






 Answer the following questions on the basis of position of elements in the above table.
(a) Which element is a noble gas? Give reason.
(b) Which element is most electronegative? Give reason.
(c) Write the electronic configuration of (i) B and (ii) E.

5 Marks Questions [ 5 x 1 = 5]

1. What are electron affinity and ionization energy? How they are vary in group and periods in modern periodic table?    OR, Two elements ‘A’ and ‘B’ belong to group 1 and 2 respectively in the same period. Compare them with respect to :–   (a) Number of valence electrons (b) Valency (c) Metallic character  (d) Size of atom (e) Formulae of their oxides.

Answer:  Read more »

Wednesday, January 2, 2013

CBSE Mathematics Sample Papers 2013-14

10th Mathematics Solved sample guess SA-II
10th Maths Sample Paper 2013 -1 Download File

10th Maths Sample Paper 2013 -2 Download File

10th Maths Sample Paper 2013 -3 Download File

10th Maths Sample Paper 2013 -4 Download File

10th Science Solved sample guess SA-II

10th Science 2013 Sample guess SA-II-paper -1         Download File

10th Science 2013 Sample guess SA-II-paper -2         Download File

X Physics + Chemistry work sheet paper-2013 - 3     Download File

10th Science 2013 Sample guess SA-II-paper -4        Download File

CBSE published Date sheet for class 10 and class 12

CBSE date sheet for class 10 and CBSE date sheet for class 12 for March 2013 exam is declared by CBSE, New Delhi at cbse official website,  CBSE exam schedule for March 2013 annual exam begins on March 01, 2013 and ends on 15th March for class 10 and on 17th April for class 12.
Saturday,02nd   March,  2013  10:30 AM
Monday,  04th   March,  2013  10:30 AM

Wednesday,06th  March,  2013  10:30 AM


Friday,08th  March,  2013  10:30 AM

Tuesday,12th  March,  2013  10:30 AM
Thursday,14th March,  2013  10:30 AM

Download Date sheet for Board Examination 2013   |   Class X   |   Class XII 
Question Papers for Board Examinations 2012 (CLASS X)
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