{"id":1828,"date":"2023-08-10T16:53:05","date_gmt":"2023-08-10T14:53:05","guid":{"rendered":"http:\/\/www.zsvltava.cz\/fyzika\/?p=1828"},"modified":"2025-04-09T11:51:50","modified_gmt":"2025-04-09T09:51:50","slug":"elektromagneticke-vlneni","status":"publish","type":"post","link":"https:\/\/www.zsvltava.cz\/fyzika\/?p=1828","title":{"rendered":"Elektromagnetick\u00e9 vln\u011bn\u00ed"},"content":{"rendered":"

Elektromagnetick\u00e9 vln\u011bn\u00ed je \u0161\u00ed\u0159en\u00ed elektrick\u00fdch a magnetick\u00fdch pol\u00ed v prostoru. Vznik\u00e1 zm\u011bnami elektrick\u00e9ho n\u00e1boje a proudu, kter\u00e9 vyvol\u00e1vaj\u00ed oscilace (kmit\u00e1n\u00ed) elektrick\u00e9ho a magnetick\u00e9ho pole.<\/strong><\/p>\n

Tyto dv\u011b slo\u017eky, elektrick\u00e1 a magnetick\u00e1, jsou na sebe navz\u00e1jem kolm\u00e9 a osciluj\u00ed v r\u016fzn\u00fdch sm\u011brech, p\u0159i\u010dem\u017e se \u0161\u00ed\u0159\u00ed spole\u010dn\u011b rychlost\u00ed sv\u011btla. Na rozd\u00edl od mechanick\u00fdch vln nepot\u0159ebuje elektromagnetick\u00e9 vln\u011bn\u00ed ke sv\u00e9mu \u0161\u00ed\u0159en\u00ed materi\u00e1ln\u00ed prost\u0159ed\u00ed, m\u016f\u017ee se \u0161\u00ed\u0159it i ve vakuu.<\/p>\n

\"\"<\/p>\n

Elektromagnetick\u00e9 vln\u011bn\u00ed se ne\u0161\u00ed\u0159\u00ed prost\u0159ednictv\u00edm \u017e\u00e1dn\u00e9ho hmotn\u00e9ho m\u00e9dia, jako jsou nap\u0159\u00edklad zvukov\u00e9 vlny v plynech, kapalin\u00e1ch nebo pevn\u00fdch l\u00e1tk\u00e1ch. <\/strong><\/p>\n

Elektromagnetick\u00e9 vlny se \u0161\u00ed\u0159\u00ed prost\u0159ed\u00edm maxim\u00e1ln\u00ed mo\u017enou rychlost\u00ed – tedy rychlost\u00ed sv\u011btla 300 000 km\/s. Vlny m\u016f\u017eou m\u00edt r\u016fznou frekvenci<\/a> a t\u00edm p\u00e1dem i vlnovou d\u00e9lku. S rostouc\u00ed frekvenc\u00ed pohybu se zkracuje vlnov\u00e1 d\u00e9lka – tedy d\u00e9lka jednoho opakov\u00e1n\u00ed. R\u016fzn\u00e9 vlnov\u00e9 d\u00e9lky (frekvence) maj\u00ed r\u016fzn\u00e9 ozna\u010den\u00ed. Ur\u010ditou frekvenci – sv\u011btlo – dokonce dok\u00e1\u017ee zachytit na\u0161e oko.<\/p>\n

Druhy elektromagnetick\u00e9ho vln\u011bn\u00ed<\/h2>\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Ozna\u010den\u00ed z\u00e1\u0159en\u00ed<\/th>\nVlnov\u00e1 d\u00e9lka λ<\/th>\n<\/tr>\n<\/thead>\n
Rozhlasov\u00e9 <\/th>\n1 km – 1m<\/td>\n<\/tr>\n
Televizn\u00ed <\/th>\n1 m – 1dm<\/td>\n<\/tr>\n
Mikrovlny <\/th>\n1 dm – 0,1 mm<\/td>\n<\/tr>\n
Infra\u010derven\u00e9 <\/th>\n0,1 mm – 1 \u00b5m<\/td>\n<\/tr>\n
Sv\u011btlo<\/th>\n1 μm \u2013 10 μm<\/td>\n<\/tr>\n
Sv\u011btlo (viditeln\u00e9)<\/th>\n400 nm \u2013 800 nm<\/td>\n<\/tr>\n
Ultrafialov\u00e9<\/th>\n10 nm – 1 nm<\/td>\n<\/tr>\n
Rentgenov\u00e9<\/th>\n1 nm – 1 pm<\/td>\n<\/tr>\n
Gama<\/th>\n< 1 pm<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

A kde je zvuk?<\/strong><\/p>\n

Zvuk nen\u00ed elektromagnetick\u00e9 vln\u011bn\u00ed. Zvuk<\/a> je vln\u011bn\u00ed mechanick\u00e9<\/strong>. Tzn., \u017ee pro sv\u00e9 \u0161\u00ed\u0159en\u00ed vyu\u017e\u00edv\u00e1 jin\u00fdch vlastnost\u00ed prost\u0159ed\u00ed.<\/p>\n

P\u016fvod elektromagnetick\u00fdch vln<\/h2>\n