Kawm cov piv txwv ntawm cov teeb meem ntawm kev cuam tshuam thiab kev diffraction ntawm lub teeb - ib qho slit , tom qab ntawd ua haujlwm rau cov teeb meem ntawm kev cuam tshuam thiab kev diffraction ntawm lub teeb.
1. Lub teeb uas muaj qhov ntev ntawm 700 nm hla dhau ib qho qhov uas muaj qhov dav ntawm 0,2 hli. Tus qauv diffraction ntawm lub vijtsam yog nyob ntawm qhov deb ntawm 50 cm ntawm qhov qhov. Txheeb xyuas qhov deb ntawm kab tsaus thib ob thiab kab teeb loj.
Kev Sib Tham
Nug tias: y?
Lus teb:
Qhov dav ntawm qhov txiav me me heev piv rau qhov deb ntawm qhov txiav thiab qhov screen (hauv daim duab qhov dav ntawm qhov txiav loj dua) yog li lub kaum sab xis me heev. Lub kaum sab xis me heev uas tus nqi ntawm sin theta ze rau tus nqi ntawm tangent theta.
Qhov kev ncua deb ntawm kab ci ntsa iab thiab kab tsaus thib ob yog 3,5 millimeters.
2. Ib qho kab uas dav li 0,1 hli raug ci los ntawm lub teeb monochromatic thiab ntawm lub vijtsam 4 meters ntawm qhov kab, ntau kab, ci thiab tsaus, tuaj yeem pom los ntawm kev diffraction. Yog tias qhov deb ntawm kab tsaus thib ob thiab kab ci tseem ceeb yog 16 hli, txiav txim siab qhov wavelength ntawm lub teeb!
Kev Sib Tham
Nws paub tias:
d = 0,1 hli = 0,0001 m = 1 x 10-4 m
l = 4 m
n = 2
y = 16 hli = 16 x 10-3 m
Nug: lub wavelength ntawm lub teeb yog dab tsi?
Lus teb:
Lub teeb ntev = 200 nanometers
3. Saib daim duab hauv qab no!
Ib qho chaw sib txawv Ib lub teeb S uas dav 0,2 hli raug ci los ntawm ib lub teeb sib luag nrog λ = 500 nm (1 nm = 10-9 m). Tus qauv diffraction tshwm sim raug ntes rau ntawm lub vijtsam 60 cm ntawm qhov slit. Qhov deb ntawm kab tsaus thib ob thiab kab kaj nruab nrab yog…
A. 3,0 hli
B. 3,6 hli
C. 4,8 hli
D. 5,8 hli
E. 6,0 hli
Kev Sib Tham
Nws yog paub :
λ = 500 nm = 500 x 10-9 m = 5 x 10-7 m
d = 0,2 hli = 0,2 x 10-3 m = 2 x 10-4 m
l = 60 cm = 0,6 m
n = 2
Nug : yog?
Jawb :
Qhov dav ntawm qhov txiav me me heev piv rau qhov deb ntawm qhov txiav thiab lub vijtsam yog li lub kaum sab xis me me heev (qhov dav ntawm qhov txiav hauv daim duab saum toj no tau nthuav dav). Lub kaum sab xis me me heev yog li tus nqi ntawm kev txhaum tus phauj kev sib txuas lus uas tab tom los txog tus phauj.
sin θ ≈ tan θ = y / l = y / 0,6
Cov mis diffraction ib qho slit (yam tsawg kawg nkaus):
d sin θ = n λ
(2 x 10 Nws-4)(y/0,6) = (2)(5 x 10-7)
(2 x 10 Nws-4) y = (0,6)(10 x 10-7)
(2 x 10 Nws-4) y = 6 x 10-7
y = (6 x 10-7) / (2 x 10-4)
y = 3 x 10-3
y = 0,003 meters
y = 3 millimeters
Cov lus teb yog lawm yog A.
4. Ib lub teeb monochromatic nrog lub wavelength ntawm 5000 Å (1 Å = 10 −10 m) hla dhau ib qho slit tsim ib qho thawj qib ci diffraction qauv raws li qhia hauv daim duab. Qhov dav ntawm qhov slit yog…
A. 0,001 hli
B. 0,004 hli
C. 0,012 hli
D. 0,017 hli
E. 0,019 hli
Kev Sib Tham
Nws yog paub :
λ = 5000 Å = 5000 x 10-10 m = 5 x 10-7 m
kev txhaum 30o = 0,5
n = 1
Nug : qhov dav ntawm qhov sib txawv (d) ?
Jawb :
d sin θ = n λ
d (0,5) = (1)(5 x 10-7)
d = (5 x 10-7) / (0,5)
d = 10 x 10-7 m
d = 1 x 10-6 m
d = 1 x 10-3 mm
d = 0,001 hli
Cov lus teb yog lawm yog A.
Kev cuam tshuam thiab diffraction ntawm lub teeb - ib qho slit
1. Ib qho qhov uas dav li 0,5 hli raug ci los ntawm lub teeb uas muaj qhov ntev ntawm 650 nm. Tus qauv diffraction ntawm lub vijtsam yog nyob ntawm qhov deb ntawm 50 cm ntawm qhov qhov. Txheeb xyuas qhov deb ntawm kab tsaus thib ob thiab kab teeb loj.
2. Ib qho qhov uas dav li 0,4 hli raug ci los ntawm lub teeb monochromatic thiab ntawm lub vijtsam 2 meters ntawm lub diffraction grating, ib qho qauv diffraction ci thiab tsaus tuaj yeem pom. Yog tias qhov deb ntawm kab tsaus thib peb thiab kab ci tseem ceeb yog 20 hli, txiav txim siab qhov wavelength ntawm lub teeb!
