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Physics, Chemistry and Biology: Post your doubts here!

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Asalam Mualakum Everyone,
I will be taking my IGCSE's in May/June 2013. Regarding chemistry and polymers what should i study ?? My teacher is not very helpful, I need your kind help and support. Are there and pdf notes for polymers??? I really need them.. and what else should i study for polymers ?? thank u....looking forward to your help.
 
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nita , physics
30- A
as you have two resistors in series total resistance = u add them up
V=IR , 6=X6 X=1 and the switch wont have any affect because its placed in a wrong way
33-B
because current behaves oppositely as magnets ! because they produce magnetic fields
Sorry, but can you explain question 33... i still dont get it!
 
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Question-
Explain why ethanol is not a carbohydrate but glucose is?

Can anyone help?
the three most essential elements that make up a carbohydrate are Carbon hydrogen and oxygen. which is present in glucose but not in alcohol which makes glucose an element of carbohydrate.
 
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Question- Suggest an explanation why butan-1-ol cannot form long polymer molecules but ethane-1,2-diol can?
butan-1-ol does not have a double bond from between two carbon atoms but ethane-1,2-diol has a double bond between carbon atoms so it can from polymers by addition polymerisation.
 
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butan-1-ol does not have a double bond from between two carbon atoms but ethane-1,2-diol has a double bond between carbon atoms so it can from polymers by addition polymerisation.
oh.. thanks!! but can the answer also be that ethane-1,2-diol has 2 OH functional groups thats why it can form longer polymers???
 
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what is the difference in but-1-ene and but-2-ene? Can you explain what the number in between stands for?
the number denotes the place where the carbon atoms are situated (but-1-ene) means that the double bond is present between first and the second carbon atom it can be written as (butene). (but-2-ene) refers to the double bonds situated between the second and the third carbon atom. Hope u understood. ;)
 
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Salam, can you please upload the IGCSE Bio, Chem and Phy past papers in the coming hours, I need them urgentally !!
 
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Which device is designed to allow a small direct current (d.c.) to control a large direct current
(d.c.)?
A a generator
B a motor
C a relay
D a transformer



and how......
 
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A relay
Remember, a relay always controls a larger current.
A relay is a switch based on the principle of an electromagnet and when the smaller current flows through the coil the electromagnet would work and attract an iron armature on a pivot, closing contacts in a second circuit witch would have a higher current.
 
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my notes in physics, i feel as they are boring, maybe someone can tell me how to grasp the topic ? as once i repeat it, i then forget about it ?? plz maybe someone can help ?thnks
 
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