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Electromagnetic Spectrum

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How do we memorise the approximate values of either the wavelength or frequency of the electromagnetic waves?
In exams we do have to make estimates.
I need to know how to learn the values of the frequencies or wavelengths of the waves, not the order in which they are present in the spectrum.
Or if there is some alternative way to tackle these e.m spectrum problems in the papers, do let me know.
Any help is appreciated.
Thanks in advance.
 
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If you have memorized the order of waves in increasing frequency or decreasing wavelengths you can use this number for WAVELENGTHS :

52212+2-1-3+2 (Memorize It)

You have to remember that they start from 10^3 and you have to subtract the numbers from 5 till 2

So for Radio subtract 5 from power, it will give you the range of wavelengths : 10^3 - 10^-2

Use 10^-2 now for Micro and subtract the second number from it that is 2... Range : 10^-2 - 10^-4

Use 10^-4 for Infrared.... And so on till Visible light...

After that you have to make the start of range yourself and its end obviously. Like for Ultraviolet it starts from 10^-9 and you have to add + 2 to it, it makes it 10^-7 (10^-9 to 10^-7)

For X-Ray subtract one from the previous 10^-7 = 10^-8 and subtract 3 from it... Range : 10^-8 to 10^-11

For frequencies use the formula v = fλ
 
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For visible light different wavelengths you know that there are 7 of the colors so it starts from 7 x 10 ^ -7 for red, subtract .5 for the next color it makes it 6.5 x 10^ -7 for Orange and keep subtracting .5 for the next color... In the end its 4 x 10^-7 for violet... Order : ROYGBIV
 

XPFMember

XPRS Moderator
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How do we memorise the approximate values of either the wavelength or frequency of the electromagnetic waves?
In exams we do have to make estimates.
I need to know how to learn the values of the frequencies or wavelengths of the waves, not the order in which they are present in the spectrum.
Or if there is some alternative way to tackle these e.m spectrum problems in the papers, do let me know.
Any help is appreciated.
Thanks in advance.
Assalamoalaikum wr wb!
so here's how I learnt it..
these are wavelengths...

write the even numbers...descending order...starts from 2 ...i start writing from down..that is -12

these are the powers of 10....check your textbook...see these ....and then learn that this value you're gonna learn is the max or the min value for that particular radiation


4 ------|
--------|
2-------|radio waves
--------|
0 ------|

-2 microwave

-4 Infra red

-6 visible light

-8 UV

-10 X-ray

-12 gamma
 
Messages
483
Reaction score
199
Points
53
If you have memorized the order of waves in increasing frequency or decreasing wavelengths you can use this number for WAVELENGTHS :

52212+2-1-3+2 (Memorize It)

You have to remember that they start from 10^3 and you have to subtract the numbers from 5 till 2

So for Radio subtract 5 from power, it will give you the range of wavelengths : 10^3 - 10^-2

Use 10^-2 now for Micro and subtract the second number from it that is 2... Range : 10^-2 - 10^-4

Use 10^-4 for Infrared.... And so on till Visible light...

After that you have to make the start of range yourself and its end obviously. Like for Ultraviolet it starts from 10^-9 and you have to add + 2 to it, it makes it 10^-7 (10^-9 to 10^-7)

For X-Ray subtract one from the previous 10^-7 = 10^-8 and subtract 3 from it... Range : 10^-8 to 10^-11

For frequencies use the formula v = fλ
Assalamoalaikum wr wb!
so here's how I learnt it..
these are wavelengths...

write the even numbers...descending order...starts from 2 ...i start writing from down..that is -12

these are the powers of 10....check your textbook...see these ....and then learn that this value you're gonna learn is the max or the min value for that particular radiation


4 ------|
--------|
2-------|radio waves
--------|
0 ------|

-2 microwave

-4 Infra red

-6 visible light

-8 UV

-10 X-ray

-12 gamma
Thanks a bunch guys!
 
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If you have memorized the order of waves in increasing frequency or decreasing wavelengths you can use this number for WAVELENGTHS :

52212+2-1-3+2 (Memorize It)

You have to remember that they start from 10^3 and you have to subtract the numbers from 5 till 2

So for Radio subtract 5 from power, it will give you the range of wavelengths : 10^3 - 10^-2

Use 10^-2 now for Micro and subtract the second number from it that is 2... Range : 10^-2 - 10^-4

Use 10^-4 for Infrared.... And so on till Visible light...

After that you have to make the start of range yourself and its end obviously. Like for Ultraviolet it starts from 10^-9 and you have to add + 2 to it, it makes it 10^-7 (10^-9 to 10^-7)

For X-Ray subtract one from the previous 10^-7 = 10^-8 and subtract 3 from it... Range : 10^-8 to 10^-11

For frequencies use the formula v = fλ

i got the one for visible light but the rest ? what is this
''52212+2-1-3+2 (Memorize It)''
 
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