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Saqiyasi Friday, September 10, 2010 01:34 AM

[QUOTE=The Star;173765]Energy can be converted into matter or other forms of energy but can not be produced.a machine can not produce energy without consuming matter or any other form of energy,it only converts one form into another.This is a well established and well known fact of mechanics.so the answer should be no.



Convection can not take place in solids.it takes place in atmosphere.cloud formation is the result of convection.convection might be correct answer.[/QUOTE]
-convection is the right answer coz radiation onli takes place where dere is no medium ..
-and conduction onli takes place onli in solids ..
-covection needs sum fluid to transfer heat. So in dis case , air acts as a fluid

Sakk Saturday, September 11, 2010 05:48 PM

[QUOTE=Saqiyasi;211956]-convection is the right answer coz radiation onli takes place where dere is no medium ..
-and conduction onli takes place onli in solids ..
-covection needs sum fluid to transfer heat. So in dis case , air acts as a fluid[/QUOTE]

Please note convection takes place in liquids, conduction takes place in solids and gases where as radiation phenomenon in which radiant energy is released is only observe if the pot containing water is heated to an extent so that it start glowing and emit light which is actually the radiant energy(e.g of radiation phenomenon is SUN emitting heat waves and if an IRON piece is put on fire for a long time so it gets really hot and emit radiation).

The answer of this very first MCQ is conduction, reason being that conduction is the gradual transfer of heat from high concentration end to lower concentration end. In this case AIR act as a medium and transfer the heat energy. The physics involve behind is that when water in pot is heated up, the high energy atoms gains energy and releases electron, thus water moecules are converted into vapors, the vapors emnating from the surface of water are hot interact with the atoms of air molecules and air molecues standing at lower energy level gains energy and starts to vibrate, this way the transfer of energy from one air molecule passes to another and spread in the near environment.

I have confirmed this with a Physics professor. Regarding those members who have written Radiation, for them radiation only takes place in electromagnetic range and in this case it is not a valid answer.

Hope this helps clarify the concept behind this tough MCQ.

Arbab Tuesday, September 28, 2010 02:55 PM

MCQ's Of EDS
 
Friends why not tabulate the MCQ's while waiting for the results.
I am giving the answers I wrote as well as the right ones if I was wrong.
Any error rectified may be appreciated.

1. C. Radiation
2. A. No
3. A. Hygrometer
4. I wrote 'C. Time Period' but it is wrong. The correct answer is 'A. Distance'
5. A. N,P,K
6. E. None of these
7. B. Non-Conductor
8. I wrote 'C. 56 ft', but it was a guess
9. A. Pitch
10. B. Transparent
11. I wrote 'B. 12 feet', but again a wild guess
12. C. Ultrasonic
13. D. Fusion nuclear reaction
14. I wrote 'E. None of thse' but it wrong. The correct answer is 'D. Distance
15. I wrote 'A. Zn+Ni' but it is wrong. The correct answer is 'C. Cu+Ni'
16. B. South Pole
17. I wrote 'D. Temp where body is kept', but a wild guess
18. C. Milk
19. I wrote 'E. None of these' but it is wrong. Plz supply the correct answer
20. B. Mariana Trench
21. Refraction of light
22. D. Decreasing focal length of the lens
23. I wrote 'A. Cu+Ni' but it is wrong. The correct answer is 'B. Copper,Tin'
24. B. Pakistan
25. I wrote 'C. Cappillarity' but i think it wrong
26. A. An equal and opposite pressure acts from inside
27. C. Nuclear Radiation
28. I wrote 'C. 7 Miles/S' but it was only a guess
29. I wrote 'D. Ultraviolet' but the right answer is 'C. Infrared'
30. I wrote 'D. Plano Convex Lens' but the answer is 'A. Convex Lens'
31. I made a wild guess of E. None of these
32. C. Richter Scale
33. A. 88 Days
34. C. Primitive
35. A. A continuing process
36. C. Mutation
37. I made a guess of D. Mutated genes
38. A. Ingestion,Digestion,Absorption,Elimination
39. C. Small Intestine
40. Essential nutrient level
41. I wrote 'D.Monosaccharide' but i think it is wrong
42. I wrote 'A. Bronchiole' but the right answer is D.Trachea
43. I wrote 'B. Fission' but not sure whether it is right or not
44. I wrote 'C. Not a Magnet' but I am definitely wrong
45. C. Nitrogen+Oxygen
46. E. None of these
47. C. Control Unit
48. C. Hydrogen
49. C. Chemotherapy & Radiotherapy
50. I wrote 'E. None of these' but it is wrong


Plz correct me augmenting facts with your answers.

goswamiraaj Thursday, September 30, 2010 06:07 PM

Well the answers of MCQs are correct but as i feel few mistakes are there which can be correct.
1. Hepatitis A is transmitted by Faeces not water.
2. Animal obtained carbohydrate from Glycogen not starch( it is used in plants)

Saad Qaisrani Thursday, September 30, 2010 07:21 PM

42. if i remeber correctly, bronchiole is correct.
44. is a strong magnet, i got this wrong
40. is actually basal metabolism. mine went wrong too.
37. is multiple genes.
24. is kenya
11. 3 feet. got this wrong too.

I know 8 of mine are confirmed wrong. I hope don't lose more than 5 others. Hopefully could end up getting 37-39 in EDS objectives.

41. should be vitamin C

As for Hepatitis A, it is a tricky question. It goes from individual to medium through faeces, but from medium to individual through water. Nobody knows what the examiner had in mind when he made the paper. i myself put water.

umarabbas Thursday, September 30, 2010 08:05 PM

Dear Sakk,

I don't know who that professor was but one thing is for sure that the type of radiation you were referring to is called "Electromagnetic Radiation" and not simple radiation.

Furthermore, for all those who think its Convection or Conduction then why is the car's radiator called called a Radiator? although the water at the surface of the radiator gets heated by conduction and then that heat spreads via convection throughout the radiator, but the heat from the radiator is transferred via radiation!! i hope this will be enough..

As far as hepatitus is concerned, it is spread by feaces. the agent that gets transfered from one body to another is the feaces. the medium through which it gets transferred is water (probably it may not be able to get transferred through air) there is a difference between agent and the medium!!!

[QUOTE=Sakk;212173]Please note convection takes place in liquids, conduction takes place in solids and gases where as radiation phenomenon in which radiant energy is released is only observe if the pot containing water is heated to an extent so that it start glowing and emit light which is actually the radiant energy(e.g of radiation phenomenon is SUN emitting heat waves and if an IRON piece is put on fire for a long time so it gets really hot and emit radiation). [/quote]

I have answered that already! that will be called Radioactive Radiation! there is a difference... the Sun does not emit radiation because it is hot. It is hot because there are is Fusion reaction going there and that is why energy is released. For Iron to emitt radiations (Electromagnetic Radition that is) one has to heat it to insanely high temperatures.




The physics involve behind is that when water in pot is heated up, the high energy atoms gains energy and releases electron, thus water moecules are converted into vapors, the vapors emnating from the surface of water are hot interact with the atoms of air molecules and air molecues standing at lower energy level gains energy and starts to vibrate, this way the transfer of energy from one air molecule passes to another and spread in the near environment.

[B]brother you have misunderstood the concept again! when water turns into vapors it does not release electrons. it just breaks the bonds between the water molecules and escape to the surrounding. it does not loose electrons. if it were loosing electrons we would not be calling water vapors (because if the number of electrons decrease/increase it turns into ions and no longer remain molecules) [/B]

Saad Qaisrani Thursday, September 30, 2010 08:41 PM

Let it be faeces, i was counting it incorrect anyways.

My take on the first one is also radiation. Conduction is impossible (air is a very poor conductor), only possibilities are convection and radiation. Infact both do occur, which is required is the issue.

What is your (Umar's ) take on objective 10? Highly confusing one it is.

umarabbas Thursday, September 30, 2010 09:01 PM

brother...the answer to this one is that light is visible....if it were not visible, dust particles or vaccum, or anything, you wouldnt be able to see it in the first place...the dust particles were just a catch..

opaque etc etc don't make any sense :)

rameeez Wednesday, October 06, 2010 09:36 PM

As an engineer its my opinion that its against basic laws of science

Dolokhov Thursday, October 07, 2010 01:52 AM

rameez
bhai do not mind
app engineer ho tu yaha aur bhi engineer hain aur i think app se better hain
agar app visibility of light k bary mein keh rahy hain k it is against the law
then app apni first term ki book physics ki book ko consult karo(used in uet first term) ye tu first term k viva ka first question hai
app hamain bhi proof ker dein to appki nawazish
hum apni mistake accept ker lein gay


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