{"id":216419,"date":"2025-12-14T14:13:17","date_gmt":"2025-12-14T13:13:17","guid":{"rendered":"https:\/\/educelec.com\/?p=216419"},"modified":"2025-12-28T17:13:46","modified_gmt":"2025-12-28T16:13:46","slug":"lois-dohm-et-calcul-de-puissance-en-regime-continu","status":"publish","type":"post","link":"https:\/\/educelec.com\/en\/lois-dohm-et-calcul-de-puissance-en-regime-continu\/","title":{"rendered":"Lois d\u2019Ohm et calcul de puissance en r\u00e9gime continu"},"content":{"rendered":"

Cet article est destin\u00e9 aux apprenants en formation professionnelle, BTS et DUT, ainsi qu\u2019aux stagiaires et techniciens souhaitant renforcer leurs bases en \u00e9lectrotechnique. La loi d\u2019Ohm et le calcul de la puissance \u00e9lectrique en r\u00e9gime continu (DC) constituent des comp\u00e9tences essentielles pour r\u00e9ussir les modules d\u2019\u00e9lectricit\u00e9, comprendre les circuits r\u00e9els et r\u00e9soudre efficacement les exercices d\u2019examen.<\/p>\n

\n

1. Qu\u2019est-ce que le r\u00e9gime continu (DC) ?<\/span><\/strong><\/h2>\n

Le r\u00e9gime continu correspond \u00e0 un circuit \u00e9lectrique o\u00f9 :<\/p>\n

la tension garde une valeur constante dans le temps,<\/p>\n

le courant circule toujours dans le m\u00eame sens.<\/p>\n

\ud83d\udc49 Exemples de sources en courant continu :<\/span><\/strong><\/h3>\n

piles et batteries,<\/p>\n

panneaux solaires,<\/p>\n

alimentations DC.<\/p>\n

\n

2. La loi d\u2019Ohm : d\u00e9finition et formule<\/strong><\/span><\/h2>\n

La loi d\u2019Ohm relie trois grandeurs \u00e9lectriques essentielles :<\/p>\n

la tension (U) en volt (V),<\/p>\n

le courant (I) en amp\u00e8re (A),<\/p>\n

la r\u00e9sistance (R) en ohm (\u03a9).<\/p>\n

Formule de la loi d\u2019Ohm ==>\u00a0 \u00a0 \u00a0 <\/span><\/strong><\/h3>\n

U = R \u00d7 I<\/strong><\/span><\/h2>\n

\u00c0 partir de cette relation, on peut aussi \u00e9crire :<\/p>\n

I = U \/ R\u00a0 \u00a0 ou\u00a0 \u00a0 \u00a0R = U \/ I<\/strong><\/span><\/h2>\n

Exemple simple :<\/strong><\/span><\/h3>\n

Si une r\u00e9sistance de 10 \u03a9 est aliment\u00e9e par une tension de 20 V, le courant est :<\/p>\n

I = 20 \/ 10 = 2 A<\/strong><\/span><\/h4>\n
\n

3. La r\u00e9sistance \u00e9lectrique<\/strong><\/span><\/h2>\n

La r\u00e9sistance repr\u00e9sente l\u2019opposition au passage du courant \u00e9lectrique. Plus la r\u00e9sistance est grande, plus le courant est faible.<\/p>\n

Elle d\u00e9pend : du mat\u00e9riau (cuivre, carbone, etc.), de la longueur du conducteur, de la section, de la temp\u00e9rature.<\/p>\n

\n

4. La puissance \u00e9lectrique en r\u00e9gime continu<\/span><\/strong><\/h2>\n

La puissance \u00e9lectrique correspond \u00e0 l\u2019\u00e9nergie consomm\u00e9e ou fournie par un r\u00e9cepteur \u00e9lectrique par unit\u00e9 de temps.<\/p>\n

Formule g\u00e9n\u00e9rale de la puissance ==><\/p>\n

P = U \u00d7 I<\/strong><\/span><\/h2>\n

 <\/p>\n

Avec :<\/p>\n

P en watt (W),<\/p>\n

U en volt (V),<\/p>\n

I en amp\u00e8re (A).<\/p>\n

Formules d\u00e9riv\u00e9es (avec la loi d\u2019Ohm)<\/span><\/strong><\/h3>\n

En combinant avec la loi d\u2019Ohm, on obtient :<\/p>\n

P = R \u00d7 I\u00b2\u00a0 \u00a0 \u00a0ou\u00a0 \u00a0 P = U\u00b2 \/ R<\/span><\/strong><\/h2>\n
\n

5. Exemple de calcul de puissance<\/strong><\/span><\/h2>\n

Soit un circuit avec : U = 12 V et I = 3 A<\/p>\n

La puissance consomm\u00e9e est :<\/p>\n

P = 12 \u00d7 3 = 36 W<\/strong><\/h4>\n

\ud83d\udc49 Cela signifie que le r\u00e9cepteur consomme 36 watts d\u2019\u00e9nergie \u00e9lectrique.<\/p>\n

\n

6. Applications pratiques<\/strong><\/span><\/h2>\n

Les lois d\u2019Ohm et de la puissance sont utilis\u00e9es pour :<\/p>\n

choisir la bonne r\u00e9sistance,<\/p>\n

dimensionner les c\u00e2bles \u00e9lectriques,<\/p>\n

calculer la puissance d\u2019un appareil,<\/p>\n

\u00e9viter les surcharges et \u00e9chauffements,<\/p>\n

comprendre les circuits solaires et batteries.<\/p>\n

\n

7. Erreurs fr\u00e9quentes \u00e0 \u00e9viter<\/strong><\/span><\/h2>\n

Confondre courant continu (DC) et courant alternatif (AC),<\/p>\n

utiliser une mauvaise formule de puissance,<\/p>\n

oublier l\u2019unit\u00e9 lors des calculs,<\/p>\n

n\u00e9gliger la valeur maximale de puissance d\u2019une r\u00e9sistance.<\/p>\n

\n

Conclusion<\/span><\/strong><\/h2>\n

La loi d\u2019Ohm et le calcul de la puissance en r\u00e9gime continu constituent la base de toute \u00e9tude en \u00e9lectricit\u00e9. Une bonne ma\u00eetrise de ces notions permet d\u2019analyser, concevoir et s\u00e9curiser efficacement les circuits \u00e9lectriques. Pour progresser davantage, il est conseill\u00e9 de s\u2019entra\u00eener avec des exercices corrig\u00e9s et des applications pratiques.<\/p>","protected":false},"excerpt":{"rendered":"

Cet article est destin\u00e9 aux apprenants en formation professionnelle, BTS et DUT, ainsi qu\u2019aux stagiaires et techniciens souhaitant renforcer leurs bases en \u00e9lectrotechnique. La loi d\u2019Ohm et le calcul de la puissance \u00e9lectrique en r\u00e9gime continu (DC) constituent des comp\u00e9tences essentielles pour r\u00e9ussir les modules d\u2019\u00e9lectricit\u00e9, comprendre les circuits r\u00e9els et r\u00e9soudre efficacement les exercices […]<\/p>","protected":false},"author":1,"featured_media":217183,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":"","om_disable_all_campaigns":false,"_uf_show_specific_survey":0,"_uf_disable_surveys":false,"footnotes":""},"categories":[27],"tags":[],"class_list":["post-216419","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-electricite"],"aioseo_notices":[],"yoast_head":"\nLois d\u2019Ohm et calcul de puissance en r\u00e9gime continu - Exercices et Solutions en Electricit\u00e9, Electronique, Electrotechnique et Automatisme industrielle<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/educelec.com\/en\/lois-dohm-et-calcul-de-puissance-en-regime-continu\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Lois d\u2019Ohm et calcul de puissance en r\u00e9gime continu - Exercices et Solutions en Electricit\u00e9, Electronique, Electrotechnique et Automatisme industrielle\" \/>\n<meta property=\"og:description\" content=\"Cet article est destin\u00e9 aux apprenants en formation professionnelle, BTS et DUT, ainsi qu\u2019aux stagiaires et techniciens souhaitant renforcer leurs bases en \u00e9lectrotechnique. La loi d\u2019Ohm et le calcul de la puissance \u00e9lectrique en r\u00e9gime continu (DC) constituent des comp\u00e9tences essentielles pour r\u00e9ussir les modules d\u2019\u00e9lectricit\u00e9, comprendre les circuits r\u00e9els et r\u00e9soudre efficacement les exercices […]\" \/>\n<meta property=\"og:url\" content=\"https:\/\/educelec.com\/en\/lois-dohm-et-calcul-de-puissance-en-regime-continu\/\" \/>\n<meta property=\"og:site_name\" content=\"Exercices et Solutions en Electricit\u00e9, Electronique, Electrotechnique et Automatisme industrielle\" \/>\n<meta property=\"article:published_time\" content=\"2025-12-14T13:13:17+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2025-12-28T16:13:46+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/educelec.com\/wp-content\/uploads\/2025\/12\/top3-1.png\" \/>\n\t<meta property=\"og:image:width\" content=\"450\" \/>\n\t<meta property=\"og:image:height\" content=\"475\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/png\" \/>\n<meta name=\"author\" content=\"admin\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"admin\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"2 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/educelec.com\/lois-dohm-et-calcul-de-puissance-en-regime-continu\/\",\"url\":\"https:\/\/educelec.com\/lois-dohm-et-calcul-de-puissance-en-regime-continu\/\",\"name\":\"Lois d\u2019Ohm et calcul de puissance en r\u00e9gime continu - Exercices et Solutions en Electricit\u00e9, Electronique, Electrotechnique et Automatisme industrielle\",\"isPartOf\":{\"@id\":\"https:\/\/educelec.com\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/educelec.com\/lois-dohm-et-calcul-de-puissance-en-regime-continu\/#primaryimage\"},\"image\":{\"@id\":\"https:\/\/educelec.com\/lois-dohm-et-calcul-de-puissance-en-regime-continu\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/educelec.com\/wp-content\/uploads\/2025\/12\/top3-1.png\",\"datePublished\":\"2025-12-14T13:13:17+00:00\",\"dateModified\":\"2025-12-28T16:13:46+00:00\",\"author\":{\"@id\":\"https:\/\/educelec.com\/#\/schema\/person\/77a4a54746e7c6eece2474c96338c6d0\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/educelec.com\/lois-dohm-et-calcul-de-puissance-en-regime-continu\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/educelec.com\/lois-dohm-et-calcul-de-puissance-en-regime-continu\/#primaryimage\",\"url\":\"https:\/\/educelec.com\/wp-content\/uploads\/2025\/12\/top3-1.png\",\"contentUrl\":\"https:\/\/educelec.com\/wp-content\/uploads\/2025\/12\/top3-1.png\",\"width\":450,\"height\":475},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/educelec.com\/#website\",\"url\":\"https:\/\/educelec.com\/\",\"name\":\"Exercices et Solutions en Electricit\u00e9, Electronique, Electrotechnique et Automatisme industrielle\",\"description\":\"WordPress\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/educelec.com\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Person\",\"@id\":\"https:\/\/educelec.com\/#\/schema\/person\/77a4a54746e7c6eece2474c96338c6d0\",\"name\":\"admin\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/educelec.com\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/f322470318adde1e50a88b55d9a1dff805ab91cd583cfb66236d8e3c7d1f74b1?s=96&d=mm&r=g\",\"contentUrl\":\"https:\/\/secure.gravatar.com\/avatar\/f322470318adde1e50a88b55d9a1dff805ab91cd583cfb66236d8e3c7d1f74b1?s=96&d=mm&r=g\",\"caption\":\"admin\"},\"url\":\"https:\/\/educelec.com\/en\/author\/admin\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Lois d\u2019Ohm et calcul de puissance en r\u00e9gime continu - Exercices et Solutions en Electricit\u00e9, Electronique, Electrotechnique et Automatisme industrielle","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/educelec.com\/en\/lois-dohm-et-calcul-de-puissance-en-regime-continu\/","og_locale":"en_US","og_type":"article","og_title":"Lois d\u2019Ohm et calcul de puissance en r\u00e9gime continu - Exercices et Solutions en Electricit\u00e9, Electronique, Electrotechnique et Automatisme industrielle","og_description":"Cet article est destin\u00e9 aux apprenants en formation professionnelle, BTS et DUT, ainsi qu\u2019aux stagiaires et techniciens souhaitant renforcer leurs bases en \u00e9lectrotechnique. 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