Question

Consider the following types of electromagnetic radiation:
(1) Microwave
(2) Ultraviolet
(3) Radio waves
(4) Infrared
(5) X-ray
(6) Visible
(a) Arrange them in order of increasing wavelength.
(b) Arrange them in order of increasing frequency.
(c) Arrange them in order of increasing energy.

Answer 1

Explanation:

Electromagnetic wave              Wavelength

(1) Microwave  =   1 m to 1 mm = $10^9 nm$ to $10^6 nm$

(2) Ultraviolet  =    10 nm to 400 nm

(3) Radio waves  =   1 mm to 100 km = $10^6 nm$ to $10^{14}nm$

(4) Infrared  =    700 nm to 1 mm

(5) X-ray  =   0.01 nm to 10 nm

(6) Visible =   400 nm t0 700 nm

a) In order of increasing wavelength:

: 5 < 2 < 6 < 4 < 1 < 3

b) Frequency of the electromagnetic wave given as:

$\nu=\frac{c}{\lambda }$

$\nu$ = frequency

$\lambda$ = Wavelength

c = speed of light

$\nu \propto \frac{1}{\lambda }$

So, the increasing order of frequency:

: 3 < 1 < 4 < 6 < 2 < 5

c) Energy(E) of the electromagnetic wave is given by Planck's equation :

$E=h\nu$

$E\propto \nu$

So, the increasing order of energy:

: 3 < 1 < 4 < 6 < 2 < 5