physics

posted by .

1) If the first order maximum of He-Ne light exits a diffraction grating at an angle of 40.7o, at what angle will the first order maximum of violet light with a wavelength of 418 nm exit?

What is He-Ne light?????

2) The most efficient antennae have a size of half the wavelength of the radiation they are emitting. How long should an antenna be to broadcast at 980 kHz?

  • physics -

    He-Ne light is a gas laser in which He is excited, and those ions then collide with Neon to release energy. Of the most common spectrums of this laser, 633 nm is the most common wavelength.

    d sinTheta=m lambda
    d = 633*E-9/sin40.7

    so, the question: d sinGamma=m lambda
    633E-9/sin40.7 * sinGamma=418E-9
    solve for The angle Gamma.

    b. 980khz*wavelenth= speed light
    solve fodr wavelength, then the size of the antenna is half that.

  • physics -

    HeNe laser operates at a wavelength of 632.8 nm in the red part of the visible spectrum

    d•sinφ = k•λ,
    for He-Ne:
    d•sin40.7º =1•632.8•10^-9….(1)
    For violet light:
    d•sinφ=1•418•10^-9 ……(2)
    Divide(1) by (2)
    d•sin40.7º/ d•sin φ =632.8•10^-9/418•10^-9,
    sinφ = sin40.7º •418/632.8 = 0.433.
    φ =arcsin 0.433 =25.68º.

    λ = c/f = 3•10^8/980000 =305.9 m
    L = λ/2 =153 m.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. physics

    Why is white light separated into a spectrum of colors when it is passed through a diffraction grating?
  2. Physics

    When light of a certain wavelength is incident normally on a certain diffraction grating the line of order 1 is at a diffraction angle of 25 degrees. The diffraction angle of the second order line is : a) 25 b) 42 c) 50 d) 58 e) 75 …
  3. PHYSICS

    1) A diffraction grating with 2.500 x 10^3 lines/cm is used to examine the sodium spectrum. Calculate the angular separation of the two closely spaced yellow lines of sodium (588.995 and 589.592) in each of the first three orders. …
  4. physics

    pleaase help me with this, i'm very bad in physics, and i mostly don't understand any of this stuff...can anyone explain as well as show me how to do this Monochromatic light from a helium-neon laser (wavelength=632.8 nm) shines at …
  5. physics

    A diffraction grating gives a second-order maximum at as angle of 31‹ for violet light (ƒÉ = 4.0 ~ 102 nm). If the diffraction grating is 1.0 cm in width, how many lines are on this diffraction grating?
  6. physics

    A diffraction grating gives a second-order maximum at as angle of 31‹ for violet light (ƒÉ = 4.0 ~ 102 nm). If the diffraction grating is 1.0 cm in width, how many lines are on this diffraction grating?
  7. Physics

    Light of wavelength 600 nm illuminates a diffraction grating. The second-order maximum is at angle 39.1°. How many lines per millimeter does this grating have?
  8. Physics

    Light containing two different wavelengths passes through a diffraction grating with 1300 slits/cm. On a screen 16.0 cm from the grating, the third-order maximum of the shorter wavelength falls midway between the central maximum and …
  9. Physics

    Diffraction grating #1 has half the lines/cm that diffraction grating #2 does. When used with a certain wavelength of light, both gratings give first order maxima. Which of the following statements is true for the same wavelength of …
  10. physics

    (a) If the first-order maximum for pure-wavelength light falling on a double slit is at an angle of 10.0º, at what angle is the second-order maximum?

More Similar Questions