enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Newton's rings - Wikipedia

    en.wikipedia.org/wiki/Newton's_rings

    Since the wavelength of light is so small, this technique can measure very small departures from flatness. For example, the wavelength of red light is about 700 nm, so using red light the difference in height between two fringes is half that, or 350 nm, about 1 ⁄ 100 the diameter of a human hair. Since the gap between the glasses increases ...

  3. Numerical aperture - Wikipedia

    en.wikipedia.org/wiki/Numerical_aperture

    As a pencil of light goes through a flat plane of glass, its half-angle changes to θ 2. Due to Snell's law, the numerical aperture remains the same: NA = n 1 sin θ 1 = n 2 sin θ 2. In optics, the numerical aperture (NA) of an optical system is a dimensionless number that characterizes the range of angles over which the system can accept or ...

  4. Multiple choice - Wikipedia

    en.wikipedia.org/wiki/Multiple_choice

    A multiple choice question, with days of the week as potential answers. Multiple choice (MC), [1] objective response or MCQ(for multiple choice question) is a form of an objective assessment in which respondents are asked to select only the correct answer from the choices offered as a list.

  5. All India Secondary School Examination - Wikipedia

    en.wikipedia.org/wiki/All_India_Secondary_School...

    All India Secondary School Examination, commonly known as the class 10th board exam, is a centralized public examination that students in schools affiliated with the Central Board of Secondary Education, primarily in India but also in other Indian-patterned schools affiliated to the CBSE across the world, taken at the end of class 10. The board ...

  6. Illuminance - Wikipedia

    en.wikipedia.org/wiki/Illuminance

    Illuminance diagram with units and terminology. In photometry, illuminance is the total luminous flux incident on a surface, per unit area. [1] It is a measure of how much the incident light illuminates the surface, wavelength-weighted by the luminosity function to correlate with human brightness perception. [2]

  7. Cauchy's equation - Wikipedia

    en.wikipedia.org/wiki/Cauchy's_equation

    The theory of light-matter interaction on which Cauchy based this equation was later found to be incorrect. In particular, the equation is only valid for regions of normal dispersion in the visible wavelength region. In the infrared, the equation becomes inaccurate, and it cannot represent regions of anomalous dispersion. Despite this, its ...

  8. Optical mark recognition - Wikipedia

    en.wikipedia.org/wiki/Optical_mark_recognition

    The first optical answer sheets were read by shining a light through the sheet and measuring how much of the light was blocked using phototubes on the opposite side. [11] As some phototubes are mostly sensitive to the blue end of the visible spectrum , [ 12 ] blue pens could not be used, as blue inks reflect and transmit blue light.

  9. Condenser (optics) - Wikipedia

    en.wikipedia.org/wiki/Condenser_(optics)

    A condenser is an optical lens that renders a divergent light beam from a point light source into a parallel or converging beam to illuminate an object to be imaged. Condensers are an essential part of any imaging device, such as microscopes , enlargers , slide projectors, and telescopes.