## Question

What is the content of energy in *X*-ray photon of wavelength 10 Ã…? Given J-s,

### Solution

According to Planck’s quantum theory, the energy of each photon of electromagnetic radiation is *hv*, where *h* is Planck’s constant and *v* is frequency of radiation, that is

Where λ is wavelength of radiation and *c* is speed of light.

#### SIMILAR QUESTIONS

In the figure given below is shown displacement-distance (*y* – *x*) graph of a transverse wave travelling along a string at the instant *t* = 0.25 *s*. At the instant *t* = 0, the end *A* of the string was in the mean position. Find out: (i) Frequency, wave-length and velocity of the wave, (ii) Equation of the wave, (iii) Displacement of B at the instant *t* = 1 second.

A transverse harmonic wave is travelling on a string with a speed of 25 m/s. A particle on the string has maximum velocity and maximum acceleration 4 m/s and 100 m/s^{2} respectively. What is the waveform?

A wave whose amplitude is 0.07m and frequency is 400 hertz travels in a medium with a velocity of 300 m/s. Determine the displacement equation of oscillation at a distance *x* metre from the source due to this wave.

What do you know about the speed of red and blue light (i) In vacuum, (ii) In glass? The refraction index of glass for blue light is 1.665 and for red light is 1.645. (The speed of light in vacuum is ).

(a) The wavelength of a given light is 0.00006 cm. Express this wavelength in micron and in angstrom.

(b) What will be its wavelength in water, if the refractive index of water be 4/3.

The wavelength of a given light in vacuum is 6400 Ã…. Calculate its wavelength in water. Refractive index of water is 4/3.

A light-ray of 6000 Ã… wavelength travelling in vacuum enters a medium of refractive index 1.5. Find the speed and the wavelength of the ray in the medium.

The absolute refractive index of air is 1.0003 and the wavelength of yellow light in vacuum is 6000 Ã…. Find the thickness of air column which will have one more wavelength of the yellow light than in the same thickness of vacuum.

The number of waves in a 4-cm thick strip of glass is the same as in 5-cm water, when the same monochromatic light travels in them. If the refractive index of water be 4/3, what will be of glass?

Calculate de-Broglie wavelength for an electron and a proton moving with the same speed of 10^{5} m/s. (*m _{e}* = 9.1×10

^{ –31}kg,

*m*= 1.67 × 10

_{p}^{ –27}kg and

*h*= 6.63 × 10

^{ –34}Js).