Answer:
Sample Response: In a vacuum, there are no atoms or particles that interfere with the path of light. However, in other media, the speed of light is lower than 3.0 × 108 m/s because the wave is continuously absorbed and re-emitted by each atom in its path. The differences in speed are due to the composition of the medium and the density of the particles in the medium.
Explanation:
Answer:
Given that refractive index of the material is √2. i.e. n = √2. Hence, critical angle for the material is 45°
The common value for “Speed of light in vacuum” is 
metre per second.
Answer: Option b
<u>Solution:
</u>
Speed of light can be defined as the speed with which light waves propagate in different medium. In vacuum, speed of light is 186,282 miles per second or 299,792 km/s which is rounded off as 
.
“Speed of light in vacuum” is a universal constant and usually represented by ‘c’. Light waves travels at a speed of 
metre per second in vacuum.
Answer:
LAW 1 : For a given metal and frequency, the number of photoelectrons emitted is directly proportional to the intensity of the incident radiation.
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LAW 2: For a given metal, there exists a certain frequency below which the photoelectric emission does not take place. This frequency is called threshold frequency.
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LAW 3: For a frequency greater than the threshold frequency, the kinetic energy of photoelectrons is dependent upon frequency or wavelength but not on the intensity of light.
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LAW 4: Photoelectric emission is an instantaneous process. The time lag between incidence of radiations and emission of electron is 10^-9 seconds.
Explanation:
