Question

The ratio of frequencies of two electromagnetic radiations is 2:1. The wavelength of first radiation is X A° and for the second radiation is 2000 A°. Then the value of X is
a)2000 A°
b)1000 A°
c)4000 A°
d)500 A°​

Answer 1

Given :

⟶ The ratio of frequencies of two electromagnetic radiations is 2 : 1

⟶ Wavelength of first and second radiations are X A° and 2000A° respectively.

To Find :

➔ Value of X.

SoluTion :

➠ Relation between frequency and wavelengh of electromagnetic radiation is given by

• f = c / λ

where,

f denotes frequency of radiation

c denotes speed of light

λ denotes wavelenth radiation

➠ We know that, speed of light has constant value therefore we can say that, frequency of radiation is inversely proportional to the wavelengh of radiation.

⇒ f / f' = λ' / λ

⇒ 2 / 1 = x / 2000

⇒ x = 2000 × 2

⇒ x = 4000 A°

Option C is the correct Answer.