 السلام عليكم ورحمة الله وبركاته
منورنا استاذنا وشرفتنا بمداخلتك الجميله ق1
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علياء الله يخليكي المحاولات حق البروف حطيها هنا ابغى اشوف انتي كيف حليتي لاني موعارف كيف ابدا فيه اصلا
وهذا حل شابتر 4
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ch4
1. how does a spectrograph work?
light passes through the slit , then up to prism which by breaking light into spectra that make it up. .
2. why is the diffraction grating more efficient than prism?
1- refracts light so no photons are "lost".
2- linear a prism disperses blue light much more than in the red .
3- gratings can also reflect light in the uv wavebands unlike a glass prism which is opaque to uv
3. what are the tools of recording the celestial object spectrum?
charged-couple device (ccd)
photographic spectra
4. what are the advantages of using the modern astronomical charged-couple devices?
1- can reach a quantum efficiency of about 90% compared with about 1% for photographic emulsions.
2- can convert almost 9 out of 10 incident photons into useful information compared with about 1 in 100 for film
3- can therefore obtain a useful spectrum much quicker than using a photographic plate
4- can obtain spectra from much fainter sources
5. what are the information of radio spectra and not available in visible spectra?
1-radio spectral data can give details about frequency and velocity.
2-it can also provide information about the polarization of the signal,
6. what is the key advantage of multifibre technique?
a key advantage of this technique is that more than one spectrum can be obtained simultaneously
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الله يعطيك العافيه
هذا حل د.علاء؟
يعني أعتمد وأرسله؟
وواجبك اللي فات وصل للدكتور؟
بالنسبه لواجب د.مجدي
بديت بمعادلة 1.3.2
وحولتها لمعادلة بدون متجهات
وفصلت الحدين كل واحد بجهه ثم كاملت
إن شاء الله يكون شرحي سهل
وإذا مافهمت قولي
بس تراها محاولة ما أظن صح
الله يجزاك خير وييسر أمرك كرفتك معاي