Babinet’s principle - Midwest

Question

A consequence of this principle used in antenna engineering states that the product of input impedances of metal and slot pieces equals the square of intrinsic impedance over four. For 10 points each:

[10h] Name this principle that states the pattern formed from an opaque body can be reformulated as a hole of the same size and shape, but with a different beam intensity.

ANSWER: Babinet’s (“bab-in-AY’s”) principle

[10e] Babinet’s principle concerns the patterns formed by this phenomenon in which light bends around an obstacle.

ANSWER: diffraction [accept diffraction patterns]

[10m] Babinet’s principle is formulated for scalar fields using this physicist’s diffraction formula, from which the Huygens–Fresnel (“HIGH-guns fren-EL”) principle is derived. This physicist described the spectra of gases in his three laws of spectroscopy.

ANSWER: Gustav Kirchhoff [or Gustav Robert Kirchhoff; accept Kirchhoff’s diffraction formula or Kirchhoff’s laws of spectroscopy]

<Purdue, Physics>

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Summary


California	2025-02-01	Y	3	13.33	67%	33%	33%
Florida	2025-02-01	Y	1	20.00	100%	100%	0%
Great Lakes	2025-02-01	Y	5	6.00	60%	0%	0%
Lower Mid-Atlantic	2025-02-01	Y	5	8.00	80%	0%	0%
Midwest	2025-02-01	Y	6	15.00	83%	33%	33%
North	2025-02-01	Y	2	10.00	100%	0%	0%
Northeast	2025-02-01	Y	4	2.50	25%	0%	0%
Pacific Northwest	2025-02-01	Y	2	15.00	100%	50%	0%
South Central	2025-02-01	Y	2	20.00	100%	50%	50%
Southeast	2025-02-01	Y	4	10.00	75%	25%	0%
Upper Mid-Atlantic	2025-02-01	Y	6	10.00	83%	17%	0%
Upstate NY	2025-02-01	Y	2	10.00	50%	50%	0%

Data


Chicago A	Illinois C	10	10	0	20
Indiana B	Chicago C	0	10	0	10
WashU A	Chicago D	0	0	0	0
Illinois A	WashU B	10	10	10	30
Indiana A	Chicago B	0	10	10	20
Missouri	Missoui S&T	0	10	0	10