Question 180: EM waves

Question

The wavelength of an X-ray beam is 10$$\mathop A\limits^o $$. The mass of a fictitious particle having the same energy as that of the X-ray photons is $${x \over 3}h$$ kg. The value of x is __________. (h = Planck's constant)

Accepted Answer

Given wavelength of an x-ray beam = 10$$\mathop A\limits^o $$
$$ \because $$ E = $${{hc} \over \lambda } = m{c^2}$$
$$ \Rightarrow $$ m = $${h \over {c\lambda }}$$
The mass of a fictitious particle having the same energy as that of the x-ray photons = $${x \over 3}$$h kg
$$ 	herefore $$ $${x \over 3}h = {h \over {c\lambda }}$$
$$x = {3 \over {c\lambda }}$$
$$ = {3 \over {3 	imes {{10}^8} 	imes 10 	imes {{10}^{ - 10}}}}$$
x = 10

EM waves

The wavelength of an X-ray beam is 10$\mathop A\limits^o . The mass of a fictitious particle having the same energy as that of the X-ray photons is {x \over 3}h$ kg. The value of x is __________. (h = Planck's constant)

Choose the correct answer: