Physics Help.. Again.

[Saad Mughal]

(e) discuss the role of the following components in the stated applications:

1. radiowaves – radio and television communications,
2. microwaves – satellite television and telephone,
3. infra-red – household electrical appliances, television controllers and intruder alarms,
4. light – optical fibres in medical uses and telephone,
5. ultra-violet – sunbeds, fluorescent tubes and sterilisation,
6. X-rays – hospital use in medical imaging and killing cancerous cells, and engineering applications such as detecting cracks in metal,
7. gamma rays – medical treatment in killing cancerous cells, and engineering applications such as detecting cracks in metal.

So, do we just have to know the applications of each of the waves or do we have to describe how they are used and what properties enable them to be used in the stated application and to what extent are they used in daily lives?

 

[asma tareen]

btw is it important to know the how to detect electomagnetic waves???

 

[Saad Mughal]

Its not there in the syllabus but when I was solving the past papers, I came across a question which asked how to detect X-rays, so its better that you learn at least one method for each.

 

[asma tareen]

hmm its the same question cux of which i asked
btw i dunno any method to detect electomagnetic waves :0

 

[Saad Mughal]

They are easy.
Just remember:
Gamma rays - G-M tube.
X-Rays - Flourescent, Photographic Plates.
Ultra Violet - Photographic Film.
Light - Eye, Photographic Film.
Infra Red - Thermometers (Blackened) (They change reading quickly in presence of infra-red waves), Special Photographic Films.
Radio Waves - Radio Aerials.

Just remember Photographic Plates are used to detect most of them

 

[asma tareen]

hmm thnx dude

 

[asma tareen]

btw can u tell me the purpose of dc motor???

 

[Saad Mughal]

 

[Saad Mughal]

DC motors use the phenomenon; Mechanical Energy = Magnetic Energy + Electrical Energy. It produces mechanical energy i.e. movement in form of rotation, it is used in many household appliances, for example, blender, toys (that move on motions), juicer, etc.
Its pretty much used in anything that produces motion in exchange for current (electrical energy).

 

[asma tareen]

ohhh i got it thnx alot

 

[Saad Mughal]

 

[Suchal Riaz]

DC motors use the phenomenon; Mechanical Energy = Magnetic Energy + Electrical Energy. It produces mechanical energy i.e. movement in form of rotation, it is used in many household appliances, for example, blender, toys (that move on motions), juicer, etc.
Its pretty much used in anything that produces motion in exchange for current (electrical energy).

if u read this statement after doing A levels u will laugh at ur innocence!

 

[Suchal Riaz]

(e) discuss the role of the following components in the stated applications:

1. radiowaves – radio and television communications,
2. microwaves – satellite television and telephone,
3. infra-red – household electrical appliances, television controllers and intruder alarms,
4. light – optical fibres in medical uses and telephone,
5. ultra-violet – sunbeds, fluorescent tubes and sterilisation,
6. X-rays – hospital use in medical imaging and killing cancerous cells, and engineering applications such as detecting cracks in metal,
7. gamma rays – medical treatment in killing cancerous cells, and engineering applications such as detecting cracks in metal.

So, do we just have to know the applications of each of the waves or do we have to describe how they are used and what properties enable them to be used in the stated application and to what extent are they used in daily lives?

u can not learn which properties enable them to work like this otherwise u will have to learn all quantum mechanics which is not in syllabus. u have to tell what role they play in each application.
for example: antennas send microwaves encoded with information to satellites in space. as light can travel through vacuum they reach satellites and then they are sent to houses where the dish receives the microwaves and decode their information.
infra-red light is emited from one side of door and is recieved by sensor on other side of door. whever some one enters the door he temporarily decrease count rate of infra-read and sensor sends signal to alarm to ring.
u hope u get it.

 

[Saad Mughal]

if u read this statement after doing A levels u will laugh at ur innocence!

Well, that's 2 years from now, and I know what you mean.
My examples are lame and in fact are wrong, I know.

 

[Saad Mughal]

u can not learn which properties enable them to work like this otherwise u will have to learn all quantum mechanics which is not in syllabus. u have to tell what role they play in each application.
for example: antennas send microwaves encoded with information to satellites in space. as light can travel through vacuum they reach satellites and then they are sent to houses where the dish receives the microwaves and decode their information.
infra-red light is emited from one side of door and is recieved by sensor on other side of door. whever some one enters the door he temporarily decrease count rate of infra-read and sensor sends signal to alarm to ring.
u hope u get it.

That's the problem. I read about their properties somewhere and so was confused.
Yeah I get it. Thanks.

 

[asma tareen]

if u read this statement after doing A levels u will laugh at ur innocence!

isnt it correct???

 

[Saad Mughal]

isnt it correct???

Yeah, sorry Asma. They're wrong.
Proper examples would be; drills, hair dryers, sewing machines and certain toys.

 

[asma tareen]

Yeah, sorry Asma. They're wrong.
Proper examples would be; drills, hair dryers, sewing machines and certain toys.

well can a water motor be an example???

 

[Umna.Asim]

Can anyone upload a pictures of block diabrams of:
1) Electricity generation from coal/oil/gas.
2)Electricity generation from nuclear power
3) Electricity generation from hydroelectric power!
Please help!

 

[Saad Mughal]

well can a water motor be an example???

I guess not since it uses the mains supply for electricity but I don't know for sure.