When we model light (EM radiation) as a particle, we call it a photon -- a packet of energy. How does this work with the model of light as a wave? To think through this, answer the following: If the intensity of a beam of light is related to the number of photons passing per second, how would you explain the intensity of light using the model of light as a wave? What feature (wavelength, frequency, amplitude, oscillation, etc.) can be a measure of intensity and why do you think so?
Stellar evolution
We may see thousands of stars in the dark sky. Our universe consists of billions of stars. Stars may appear tiny to us but they are huge balls of gasses. Sun is a star of average size. Some stars are even a thousand times larger than the sun. The stars do not exist forever they have a certain lifetime. The life span of the sun is about 10 billion years. The star undergoes various changes during its lifetime, this process is called stellar evolution. The structure of the sun-like star is shown below.
Red Shift
It is an astronomical phenomenon. In this phenomenon, increase in wavelength with corresponding decrease in photon energy and frequency of radiation of light. It is the displacement of spectrum of any kind of astronomical object to the longer wavelengths (red) side.
This property of light as a photon can be illustrated by photoelectric effect i.e. When a light of a particular frequency falls on a metal surface attached to a sensing device like a voltmeter then on absorbing photon electrons are emitted from the emetal surface and the voltmeter deflects.
Also using the Davision and Garmer experiment this photon nature of light can be determined and angle at which this light falls on the metal surface was found perfect at 54 degree ad the wavelength can also be calculated using
lambda=1.227/ m-1
This proves the wave nature of light.
As the wave is travelling at speed of light the frequency can be calculated by-
Frequency F= C/Lmbda
where C is the speed of light =3x108m/s
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