Friday, July 4, 2014

SOLID STATE EAMCET MCQ’S
1. Which of the following conditions favours the existence of a substance in the
solid state?
(i) High temperature
(ii) Low temperature
(iii) High thermal energy
(iv) Weak cohesive forces
2. Which of the following is not a characteristic of a crystalline solid?
(i) Definite and characteristic heat of fusion.
(ii) Isotropic nature.
(iii) A regular periodically repeated pattern of arrangement of constituent
particles in the entire crystal.
(iv) A true solid
3. Which of the following is an amorphous solid?
(i) Graphite (C)
(ii) Quartz glass (SiO2)
(iii) Chrome alum
(iv) Silicon carbide (SiC)
4. Which of the following is true about the value of refractive index of quartz glass?
(i) Same in all directions
(ii) Different in different directions
(iii) Cannot be measured
(iv) Always zero
5. Which of the following statement is not true about amorphous solids?
(i) On heating they may become crystalline at certain temperature.
(ii) They may become crystalline on keeping for long time.
(iii) Amorphous solids can be moulded by heating.
(iv) They are anisotropic in nature.
6. The sharp melting point of crystalline solids is due to ___________.
(i) a regular arrangement of constituent particles observed over a short
distance in the crystal lattice.
(ii) a regular arrangement of constituent particles observed over a long
distance in the crystal lattice.
(iii) same arrangement of constituent particles in different directions.
(iv) different arrangement of constituent particles in different directions.
7. Iodine molecules are held in the crystals lattice by ____________.
(i) london forces
(ii) dipole-dipole interactions
(iii) covalent bonds
(iv) coulombic forces
8. Which of the following is a network solid?
(i) SO2 (Solid)
(ii) I2
(iii) Diamond
(iv) H2O (Ice)
9. Which of the following solids is not an electrical conductor?
(A) Mg (s) (B) TiO (s) (C) I2 (s) (D) H2O (s)
(i) (A) only
(ii) (B) Only
(iii) (C) and (D)
(iv) (B), (C) and (D)
 10. Which of the following is not the characteristic of ionic solids?
(i) Very low value of electrical conductivity in the molten state.
(ii) Brittle nature.
(iii) Very strong forces of interactions.
(iv) Anisotropic nature.
11. Graphite is a good conductor of electricity due to the presence of __________.
(i) lone pair of electrons
(ii) free valence electrons
(iii) cations
(iv) anions
12. Which of the following oxides behaves as conductor or insulator depending
upon temperature?
(i) TiO
(ii) SiO2
(iii) TiO3
(iv) MgO
13. Which of the following oxides shows electrical properties like metals?
(i) SiO2
(ii) MgO
(iii) SO2(s)
(iv) CrO2
14. The lattice site in a pure crystal cannot be occupied by _________.
(i) molecule
(ii) ion
(iii) electron
(iv) atom
15. Graphite cannot be classified as __________.
(i) conducting solid
(ii) network solid
(iii) covalent solid
(iv) ionic solid
16. Cations are present in the interstitial sites in __________.
(i) Frenkel defect
(ii) Schottky defect
(iii) Vacancy defect
(iv) Metal deficiency defect
17. Schottky defect is observed in crystals when __________.
(i) some cations move from their lattice site to interstitial sites.
(ii) equal number of cations and anions are missing from the lattice.
(iii) some lattice sites are occupied by electrons.
(iv) some impurity is present in the lattice.
18. Which of the following is true about the charge acquired by p-type
semiconductors?
(i) positive
(ii) neutral
(iii) negative
(iv) depends on concentration of p impurity
19. To get a n-type semiconductor from silicon, it should be doped with a
substance with valence__________.
(i) 2
(ii) 1
(iii) 3
(iv) 5
20. The total number of tetrahedral voids in the face centred unit cell is __________.
(i) 6
(ii) 8
(iii) 10
(iv) 12
21. Which of the following point defects are shown by AgBr(s) crystals?
(A) Schottky defect (B) Frenkel defect
(C) Metal excess defect (D) Metal deficiency defect
(i) (A) and (B)
(ii) (C) and (D)
(iii) (A) and (C)
(iv) (B) and (D)
22. In which pair most efficient packing is present?
(i) hcp and bcc
(ii) hcp and ccp
(iii) bcc and ccp
(iv) bcc and simple cubic cell
23. Which of the following statement is not true about the hexagonal close
packing?
(i) The coordination number is 12.
(ii) It has 74% packing efficiency.
(iii) Tetrahedral voids of the second layer are covered by the spheres of the
third layer.
(iv) In this arrangement spheres of the fourth layer are exactly aligned with
those of the first layer.
24. In which of the following structures coordination number for cations and
anions in the packed structure will be same?
(i) Cl– ion form fcc lattice and Na+ ions occupy all octahedral voids of the
unit cell.
(ii) Ca2+ ions form fcc lattice and F – ions occupy all the eight tetrahedral
voids of the unit cell.
(iii) O2– ions form fcc lattice and Na+ ions occupy all the eight tetrahedral
voids of the unit cell.
(iv) S2– ions form fcc lattice and Zn2+ ions go into alternate tetrahedral voids
of the unit cell.
25. What is the coordination number in a square close packed structure in two
dimensions?
(i) 2
(ii) 3
(iii) 4
(iv) 6
26. Which kind of defects are introduced by doping?
(i) Dislocation defect
(ii) Schottky defect
(iii) Frenkel defects
(iv) Electronic defects
27. Silicon doped with electron-rich impurity forms ________.
(i) p-type semiconductor
(ii) n-type semiconductor
(iii) intrinsic semiconductor
(iv) insulator
28. Which of the following statements is not true?
(i) Paramagnetic substances are weakly attracted by magnetic field.
(ii) Ferromagnetic substances cannot be magnetised permanently.
(iii) The domains in antiferromagnetic substances are oppositely oriented
with respect to each other.
(iv) Pairing of electrons cancels their magnetic moment in the diamagnetic
substances.
29. Which of the following is not true about the ionic solids?
(i) Bigger ions form the close packed structure.
(ii) Smaller ions occupy either the tetrahedral or the octahedral voids
depending upon their size.
(iii) Occupation of all the voids is not necessary.
(iv) The fraction of octahedral or tetrahedral voids occupied depends upon
the radii of the ions occupying the voids.
30. A ferromagnetic substance becomes a permanent magnet when it is placed in
a magnetic field becuase ________.
(i) all the domains get oriented in the direction of magnetic field.
(ii) all the domains get oriented in the direction opposite to the direction of
magnetic field.
(iii) domains get oriented randomly.
(iv) domains are not affected by magnetic field.
31. The correct order of the packing efficiency in different types of unit cells is ________.
(i) fcc < bcc < simple cubic
(ii) fcc > bcc > simple cubic
(iii) fcc < bcc > simple cubic
(iv) bcc < fcc > simple cubic
32. Which of the following defects is also known as dislocation defect?
(i) Frenkel defect
(ii) Schottky defect
(iii) Non-stoichiometric defect
(iv) Simple interstitial defect
33. In the cubic close packing, the unit cell has ________.
(i) 4 tetrahedral voids each of which is shared by four adjacent unit cells.
(ii) 4 tetrahedral voids within the unit cell.
(iii) 8 tetrahedral voids each of the which is shared by four adjacent unit
cells.

(iv) 8 tetrahedral voids within the unit cells.

Thursday, July 3, 2014

AIR AROUND US                               
1. To walk through a waterlogged area, you usually shorten the length of your dress by folding it. Can be reversed?
Yes. This change can be reversed.
2.You accidentally dropped your favorite toy and brokeit.This is a change you did not want.Can this change be reverded?
No.This change cannot be reversed
3.Some changes are listed in the following table.For each change.write in the blank column,whether the change be reversed or not?
Sl.no
change
Can be reversed
(Yes/No)
1.
2.
3.
4.
5.
6.
The sawing of a piece of wood
The melting of ice candy
Dissolving sugar in water
The cooking of food
The ripening of a mango
Souring of milk
No
Yes
Yes
No
No
No

4.A drawing sheet change when you draw a picture on it.Can you reverse this change?
If the picture is drawn a pencil, then it can be erased, hence change can be reversed.But if picture is drawn with clours, the change cannot be reversed.
5.Give examples to explain the difference between change that can or cannot be reversed?
Some changes can be reversed,like
1)Filling water with glass
2)Opening/Closing door.
Other change cannot be reversed,like
1)Cording of milk
2) Ripening of fruit
6.A thin coating of a paste of plaster of paris is applied over the bandage on a fractured bone.It becomes hard on drying to keep the fractured bone immobilized.Can the change inPOP be reversed?
No.The change in POP cannot be reversed.
7.A bag of cement lying in the open gets wet due to rain during the night.The next day the sum shines brightly.Do you think the changes which have occurred in the cement could be reversed?
No.the changes which have occurred in the cement cannot  be reversed


SEPERATION OF SUBSTANCES
Question: 1. Why do we need to separate different components of a mixture? Give two examples.
Answer- A mixture may contain one or more unwanted substances which may be harmful.
These impurities are harmful for our health so, we need to separate different components of a mixture. Examples: Pebbles are separated from rice and pulse. Petrol, diesel, kerosene, etc. are obtained from crude oil by a method called distillation.
Question: 2. What is winnowing? Where is it used?
Answer-The process of separation of grains from husk and hay with the help of wind is called winnowing. Farmers use this method for separating the grains from husk and hay.
Question: 3. How will you separate husk or dirt particles from a given sample of pulses before cooking?
Answer: For this, winnowing can be used.
Question: 4. What is sieving? Where is it used?
Answer-The process of separating solid constituents of different particle sizes; through a sieve is called sieving. Sieving is used while separating bran from flour. It is also used while separating pebbles from sand.
Question: 5. How will you separate sand and water from their mixture?
Answer- The mixture of sand and water can be separated by sedimentation and decantation.
Question: 6. Is it possible to separate sugar mixed with wheat flour? If yes, how will do it?
Answer: Yes, it is possible to separate sugar mixed with wheat flour. It can be done by the process of sieving.
Question: 7. How would you obtain clear water from a sample of muddy water?
Answer- We can get clear water from a sample of muddy water by the process of sedimentation, decantation and filtration. Coarser particles of soil would settle down at the bottom and partially clean water can be separated by decantation. The water thus obtained can be further clarified by filtration.
Question: 8. Fill in the blanks.
(a) The method of separating seeds of paddy from its stalks is called---------.
Answer- threshing
(b) When milk, cooled after boiling, is poured onto a piece of cloth the cream (malai) is left behind on it. This process of separating cream from milk is an example of -------
Answer- filtration
(c) Salt is obtained from sea water by the process of -------
Answer- evaporation
(d) Impurities settled at the bottom when muddy water was kept overnight in a bucket. The clear water was then poured off from the top.
The process of separations used in this example is called------------
Answer- sedimentation and decantation
Question: 9 - True or false?
(a) A mixture of milk and water can be separated by filtration. (F)
(b) A mixture of powdered salt and sugar can be separated by the process of winnowing. (F)
(c) Separation of sugar from tea can be done with filtration. (F)
(d) Grain and husk can be separated with the process of decantation. (F)
Question: 10 - Lemonade is prepared by mixing lemon juice and sugar in water. You wish to add ice to cool it. Should you add to the lemonade before or after dissolving sugar? In which case would it be possible to dissolve more sugar?
Answer: Ice should be added after dissolving the sugar. Saturation level increases with increase in temperature and vice-versa is also true. So, it is possible to dissolve more sugar in water at room temperature rather than at lesser temperature.
Additional Questions Based on Separation of Substances
Multiple Choice Questions
Question: 1. The process of settling down of particles of insoluble solid in a liquid is called
(a) Decantation
(b) sieving
(c) sedimentation
(d) winnowing
Answer- (c) sedimentation.
Question: 2. A solid substance is dissolved in water. Which of the following methods should be used for separating it?
(a) distillation
(b) evaporation
(c) decantation
(d) filtration
Answer- (b) evaporation
Question: 3. Which of the following properties of particles is ideal for winnowing?
(a) Difference in size
(b) difference in colour
(c) difference in weight
(d) difference in shape.
Answer: (c) difference in weight
Question: 4. Which of the following methods is used in separation of chaff from wheat?
(a) handpicking
(b) sieving
(c) Winnowing
(d) sublimation
Answer: (c) Winnowing
Question: 5. Which of the following methods is used in separation of pebbles from rice?
(a) sieving
(b) Winnowing
(c) sublimation
(d) Handpicking

Answer- (d) Handpicking
SORTING MATERIALS INTO GROUPS
Question: 1. Name the objects which can be made from iron and wood.
Answer: Wooden items: window, door, sofa, chair, etc.
Iron items: Car, truck, bridge, utensil, grill, etc.
Question: 2. Select those objects from the following which shine.
Glass bowl, plastic toy, steel spoon, cotton shirt.
Answer: Glass bowl and steel spoon
Question: 3. Match the objects given below with the materials from which they could be made. Remember, an object could be made from more than one material and a given material could be used for making many objects.
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Question: 4. State whether the statements given below are True or false.
(a) Stone is transparent, while glass is opaque. (F)
(b) A notebook has luster, while eraser does not. (F)
(c) Chalk dissolves in water. (F)
(d) A piece of wood floats on water. (T)
(e) Oil mixes with water. (F)
(f) Sand settles down in the water. (T)
(g) Vinegar dissolves in water. (T)
Question: 5. Given below are names of some objects and materials.
Water, basketball, orange, sugar, globe, apple and earthen pitcher.
Group them as:
(a) Round shaped and other shapes.
Answer: Round-shaped: Basketball, orange, globe and earthen pitcher.
(b) Eatables and non eatables
Answer: Eatables: Water, orange, sugar and apple.
Non-eatables: Basketball, globe and earthen pitcher.
Question: 6. List all items known to you that float on water. Check and see if they will float on an oil or kerosene.
Answer: Items; like wood, cork, Styrofoam, etc. float on water as well as on oil.
Question: 7. Find the odd one out from the following.
(a) Chair, bed, table, baby, cupboard
Answer: Baby is a living being, while others are non-living.
(b) Rose, jasmine, Boat, Marigold, Lotus.
Answer- Boat is a mode of transport, while others are flowers.
(c) Aluminium, iron, copper, silver, sand.
Answer: Sand is non-metal, while others are metals.
(d) Sugar, Salt, sand, copper sulphate.
Answer: Sand is insoluble in water, while others are soluble in water.
Extra Questions
Answer the following questions-
Question: 1. Name two materials which are soluble in water.
Answer- Sugar and salt.
Question: 2. Name two transparent and two opaque materials.
Answer- Glass, acrylic sheet are transparent materials, while stone and wood are opaque materials.
Question: 3. What are metals?
Answer- The substance which is hard, has luster and is good conductor of heat and electricity is called metal.
Question: 4. What is transparent material?
Answer: The material which allows light to pass through it is called transparent materials.
Multiple choice questions-
Question: 1. Which of the following is soluble in water?
(a) Sand
(b) Oil
(c) Glycerine
(d) Iron filing
Answer: - (c) Glycerine
Question: 2. Which of the following is insoluble in water?
(a) Chalk
(b) Washing soda
(c) Lemon juice
(d) Sugar
Answer: - (a) Chalk
Question: 3. Which of the following is a soft material?
(a) Iron
(b) Glass
(c) Dimond
(d) Chalk
Answer: - (d) Chalk
Question: 4. Which of the following is a hard material?
(a) Chalk
(b) Wool
(c) Cotton
(d) Diamond
Answer: - (d) Diamond
Question: 5. Which of the following can float on water?
(a) Iron pin
(b) Wood
(c) Steel
(d) Coin
Answer: - (b) Wood
Question: 6. Which of the following materials would sink in water?
(a) Steel spoon
(b) Piece of wood
(c) Pencil
(d) Toothbrush

Answer: - (a) Steel spoon
FIBRE TO FABRIC
Question: 1. Classify the following fibre as natural or synthetic.
Nylon, Wool, Cotton, Silk, Polyester and Jute
Answer- Nylon and polyester are synthetic fibre.
Wool, cotton, silk and jute are natural fibre.
Question: 2. State whether the following statements are true or false.
(a) Yarn is made from fibre. (T)
(b) Spinning is a process of making fibre. (T)
(c) Jute is the outer covering of coconut. (F)
(d) The process of removing seed from cotton is called ginning. (T)
(e) Weaving of yarn makes a piece of fabric. (T)
(f) Silk fiber is obtained from the stem of a plant. (F)
(g) Polyester is a natural fiber. (T)
Question: 3. Fill in the blanks:
(a) Plant fibre are obtained from------ and------
Answer: - plants and animals.
(b) Animals fibre are-------- and -------
Answer: - wool and silk.
Question: 4 - From which parts of the plant cotton and jute are obtained?
Answer- Cotton is obtained from fruits of cotton plant and jute is obtained from stem of the jute plant.
Question: 5 - Name two items that are made from coconut fiber.
Answer: - Rope and doormats.
Question: 6 - Explain the process of making yarn from fiber.
Answer: Fiber is made from yarn by spinning. Spinning is done manually as well as using machines by twisting fiber; like rope making.
Extra Questions: -
Answer the following Questions: -
Questions: 1. Question- Which part of plants give us jute and coir?
Answer: Jute comes from the stem of jute plants, while coir comes from the husk of coconut fruit.
Questions: 2. Question- What is ginning?
Answer- The process of removing cotton seeds from cotton pods is called ginning.
Questions: 3. Question- What is spinning?
Answer- The process of making yarn from fibre is called spinning.
Questions: 4. Mention uses of jute fibre?
Answer- Jute is used mainly for making gunny bags, shopping bags, ropes, carpets, etc.
Questions: 5. Write the name of some manmade fibre?
Answer: Rayon, nylon, polyester, acrylic, etc.
Questions: 6. Write the name of animal fibre?
Answer- Silk and wool.
Questions: 7. What is caterpillar?
Answer: The larva of silk-moth is called caterpillar.
Questions: 8. Why do we need to wear clothes?
Answer- Clothes protect us from heat, cold and rain.
Multiple type questions: -
Questions: 1. Which of the following is obtained from natural sources?
(a) Wool
(b) Nylon
(c) Polyester
(d) Acrylic
Answer: - (a) Wool
Questions: 2. Which of the following is obtained from animals?
(a) Jute and cotton.
(b) Nylon and polyester
(c) Wool and silk
(d) Rayon and acrylic
Answer: - (c) Wool and Silk
Questions: 3. Silk worms are reared on which of these?
(a) On leaves of mulberry plant
(b) On the leaves of banyan plant
(c) On the leaves of spinach plant
(d) On the leaves of cotton plant
Answer: - (a) On leaves of mulberry plant
Questions: 4. Which of the following animals give wool?
(a) Sheep and yak
(b) Elephant and tiger
(c) Cow and dog
(d) Snake and duck
Answer: - (a) Sheep and yak
Questions: 5. Which of the following is obtained from hair of an animal?
(a) Silk
(b) Cotton
(c) Nylon
(d) Wool
Answer: - (d) Wool
Questions: 6. What is the name of process which involves pulling and twisting of strands of a fibre?
(a) Ginning
(b) Weaving
(c) Spinning
(d) None of these.
Answer: - (c) Spinning
Questions: 7. Which is the right time to cut jute plants?
(a) Flowering stage
(b) Mature stage
(c) Before flowering stage
(d) Any time after flowering.
Answer: - (a) Flowering stage
Questions: 8. Which part of the jute plant does give fibre?
(a) Root
(b) Stem
(c) Leaf
(d) Flower

Answer: - (b) Stem