Tag: light, shadows and images

Questions Related to light, shadows and images

What is the wavelength range of visible light?

evs light, shadows and images what makes things visible nature and sources of light light travels in straight line

  1. $ 4 \times 10^{-7} m $ to $ 8 \times 10^{-7} m$

  2. $ 4 \times 10^{-9} m $ to $ 8 \times 10^{-9} m$

  3. $ 4 \times 10^{-5} m $ to $ 8 \times 10^{-5} m$

  4. $ 4 \times 10^{-6} m $ to $ 8 \times 10^{-6} m$

Show answer
Correct Option: A
Explanation:

The wavelength of visible light lies between $400\,{\rm{nm}}$ to $800\,{\rm{nm}}$.

Or, $4 \times {10^{ - 7}}$ to $8 \times {10^{ - 7}}\,{\rm{m}}$

 

In a YDSE with two identical slits, when the upper slit is covered with a thin, perfectly transparent sheet of mica, the intensity at the centre of screen reduces to $75\%$ of the initial value. Second minima is observed to be above this point and third maxima below it. Which of the following can be a possible value of phase difference caused by the mica sheet.

evs light, shadows and images what makes things visible nature and sources of light light travels in straight line

  1. $\dfrac{\pi}{3}$

  2. $\dfrac{13\pi}{3}$

  3. $\dfrac{17\pi}{3}$

  4. $\dfrac{11\pi}{3}$

Show answer
Correct Option: D
Explanation:

Here when second order minica replaces bright spot change in path difference$3\pi $


Second order minica phase difference$\dfrac { \pi  }{ 2 } $

Phase difference lies between $3\pi\ to\ 4\pi $ i.e. $\dfrac{11\pi}{3}$