电流是标量，但为什么有方向 电流是标量，但为什么有方向？
\u7535\u6d41\u6709\u5927\u5c0f\u6709\u65b9\u5411\u4f46\u4e3a\u4ec0\u4e48\u662f\u6807\u91cf\u79d1\u5b66\u4e0a\u628a\u5355\u4f4d\u65f6\u95f4\u91cc\u901a\u8fc7\u5bfc\u4f53\u4efb\u4e00\u6a2a\u622a\u9762\u7684\u7535\u91cf\u53eb\u505a\u7535\u6d41\u5f3a\u5ea6\uff0c\u7b80\u79f0\u7535\u6d41\u3002\u901a\u5e38\u7528\u5b57\u6bcd I\u8868\u793a\uff0c\u5b83\u7684\u5355\u4f4d\u662f\u5b89\u57f9\uff08\u5b89\u5fb7\u70c8\u00b7\u739b\u4e3d\u00b7\u5b89\u57f9\uff09\uff0c1775\u5e74\u20141836\u5e74\uff0c\u6cd5\u56fd\u7269\u7406\u5b66\u5bb6\u3001\u5316\u5b66\u5bb6\uff0c\u5728\u7535\u78c1\u4f5c\u7528\u65b9\u9762\u7684\u7814\u7a76\u6210\u5c31\u5353\u8457\uff0c\u5bf9\u6570\u5b66\u548c\u7269\u7406\u4e5f\u6709\u8d21\u732e\u3002\u7535\u6d41\u7684\u56fd\u9645\u5355\u4f4d\u5b89\u57f9\u5373\u4ee5\u5176\u59d3\u6c0f\u547d\u540d\uff09\uff0c\u7b80\u79f0\u201c\u5b89\u201d\uff0c\u7b26\u53f7 \u201cA\u201d\uff0c\u4e5f\u662f\u6307\u7535\u8377\u5728\u5bfc\u4f53\u4e2d\u7684\u5b9a\u5411\u79fb\u52a8\u7684\u73b0\u8c61\u3002
\u5bfc\u4f53\u4e2d\u7684\u81ea\u7531\u7535\u8377\u5728\u7535\u573a\u529b\u7684\u4f5c\u7528\u4e0b\u505a\u6709\u89c4\u5219\u7684\u5b9a\u5411\u8fd0\u52a8\u5c31\u5f62\u6210\u4e86\u7535\u6d41\u3002
\u7535\u6e90\u7684\u7535\u52a8\u52bf\u5f62\u6210\u4e86\u7535\u538b\uff0c\u7ee7\u800c\u4ea7\u751f\u4e86\u7535\u573a\u529b\uff0c\u5728\u7535\u573a\u529b\u7684\u4f5c\u7528\u4e0b\uff0c\u5904\u4e8e\u7535\u5fae\u5b89(\u03bcA)1A=1 000mA=1 000 000\u03bcA\uff0c\u7535\u5b66\u4e0a\u89c4\u5b9a\uff1a\u6b63\u7535\u8377\u5b9a\u5411\u6d41\u52a8\u7684\u65b9\u5411\u4e3a\u7535\u6d41\u65b9\u5411\u3002\u91d1\u5c5e\u5bfc\u4f53\u4e2d\u7535\u6d41\u5fae\u89c2\u8868\u8fbe\u5f0fI=nesv,n\u4e3a\u5355\u4f4d\u4f53\u79ef\u5185\u81ea\u7531\u7535\u5b50\u6570\uff0ce\u4e3a\u7535\u5b50\u7684\u7535\u8377\u91cf\uff0cs\u4e3a\u5bfc\u4f53\u6a2a\u622a\u9762\u79ef\uff0cv\u4e3a\u7535\u8377\u901f\u5ea6\u3002
\u5927\u81ea\u7136\u6709\u5f88\u591a\u79cd\u627f\u8f7d\u7535\u8377\u7684\u8f7d\u5b50\uff0c\u4f8b\u5982\uff0c\u5bfc\u7535\u4f53\u5185\u53ef\u79fb\u52a8\u7684\u7535\u5b50\u3001\u7535\u89e3\u6db2\u5185\u7684\u79bb\u5b50\u3001\u7b49\u79bb\u5b50\u4f53\u5185\u7684\u7535\u5b50\u548c\u79bb\u5b50\u3001\u5f3a\u5b50\u5185\u7684\u5938\u514b\u3002\u8fd9\u4e9b\u8f7d\u5b50\u7684\u79fb\u52a8\uff0c\u5f62\u6210\u4e86\u7535\u6d41\u3002
1\u5b89\u57f9\u7684\u5b9a\u4e49\uff1a1\u79d2\u5185\u901a\u8fc7\u5bfc\u4f53\u6a2a\u622a\u9762\u7684\u7535\u8377\u91cf\u4e3a1\u5e93\u4ed1\u3002\u5b89\u57f9\u662f\u56fd\u9645\u5355\u4f4d\u5236\u4e2d\u7535\u6d41\u7684\u57fa\u672c\u5355\u4f4d\u3002
1A=1000mA
1mA=1000\u03bcA
\u7269\u7406\u4e0a\u89c4\u5b9a\u7535\u6d41\u7684\u65b9\u5411\uff0c\u662f\u6b63\u7535\u8377\u5b9a\u5411\u8fd0\u52a8\u7684\u65b9\u5411\uff08\u5373\u6b63\u7535\u8377\u5b9a\u5411\u8fd0\u52a8\u7684\u65b9\u5411\uff09\u3002\u7535\u6d41\u8fd0\u52a8\u65b9\u5411\u4e0e\u7535\u5b50\u8fd0\u52a8\u65b9\u5411\u76f8\u53cd\u3002
\u7535\u8377\u6307\u7684\u662f\u81ea\u7531\u7535\u8377\uff0c\u5728\u91d1\u5c5e\u5bfc\u4f53\u4e2d\u7684\u81ea\u7531\u7535\u8377\u662f\u81ea\u7531\u7535\u5b50\uff0c\u5728\u9178\uff0c\u78b1\uff0c\u76d0\u7684\u6c34\u6eb6\u6db2\u4e2d\u662f\u6b63\u79bb\u5b50\u548c\u8d1f\u79bb\u5b50\u3002
\u5e0c\u671b\u6211\u80fd\u5e2e\u52a9\u4f60\u89e3\u7591\u91ca\u60d1\u3002\u5728\u7535\u6e90\u5916\u90e8\u7535\u6d41\u7531\u6b63\u6781\u6d41\u5411\u8d1f\u6781\u3002\u5728\u7535\u6e90\u5185\u90e8\u7531\u8d1f\u6781\u6d41\u56de\u6b63\u6781\u3002
\u4e00\u697c\u8bf4\u7684\u4e5f\u6ca1\u9519\uff0c\u4f46\u662f\u6ca1\u6709\u8bf4\u5230\u697c\u4e3b\u6240\u63d0\u51fa\u95ee\u9898\u7684\u70b9\u4e0a\u3002\u6211\u505a\u4e00\u70b9\u8865\u5145\u5427\u3002
\u7535\u6d41\u7684\u65b9\u5411\u662f\u4e3a\u4e86\u6839\u636e\u7535\u538b\u7684\u65b9\u5411\u800c\u786e\u5b9a\u7684\u3002\u6b64\u65f6\u7684\u7535\u6d41\u65b9\u5411\u4e0e\u7535\u538b\u65b9\u5411\u4e00\u6837\u662f\u4e3a\u4e86\u533a\u522b\u4e8e\u4e0d\u540c\u7535\u538b\uff0c\u800c\u4e0d\u662f\u5355\u7eaf\u7684\u4e00\u4e2a\u77e2\u91cf\u3002
\u56e0\u4e3a\u5927\u5bb6\u90fd\u77e5\u9053\u7535\u538b\u7684\u65b9\u5411\u4e0d\u5728\u4e4e\u4ee3\u8868\u6b63\u7535\u538b\u548c\u8d1f\u7535\u538b\u4e24\u4e2a\u65b9\u5411\uff0c\u4f46\u73b0\u5b9e\u751f\u6d3b\u4e2d\u7684\u7535\u538b\u91cf\u5927\u5c0f\u662f\u6210\u6b63\u5f26\u6ce2\u7684\u6ce2\u5f62\u6765\u8f93\u51fa\u7684\uff0c\u4e5f\u5c31\u662f\u540c\u5927\u5c0f\u7535\u538b\uff08\u8fd9\u65f6\u662f\u8bf4\u7684\u5e73\u5747\u7535\u538b\uff09\u4e0b\u7684\u540c\u4e00\u65f6\u523b\uff08\u6b64\u65f6\u95f4\u662f\u8bf4\u7684\u662f\u77ac\u95f4\uff09\u7535\u538b\u662f\u4e0d\u4e00\u6837\u7684\uff08\u5bf9\u5e94\u5728\u6b63\u5f26\u6ce2\u7684\u4e0d\u540c\u6ce2\u6bb5\u4e2d\u3002\uff09\u3002\u6240\u4ee5\u4e3a\u4e86\u533a\u522b\u4e0d\u540c\u7684\u7535\u538b\uff0c\u7535\u529b\u4e0a\u5b9a\u4e49\u4e86\u4e00\u4e2a\u7535\u89d2\u5ea6\u6765\u533a\u522b\u4e0d\u540c\u7684\u7535\u538b\u3002
\u800c\u6b64\u65f6\u7535\u538b\u5982\u679c\u63a5\u5165\u7eaf\u7535\u963b\u5143\u4ef6\u7684\u8bdd\uff0c\u7535\u6d41\u7535\u89d2\u5ea6\u4e0e\u7535\u538b\u7535\u89d2\u5ea6\u4e00\u6837\uff0c\u800c\u5982\u679c\u6b64\u7535\u538b\u63a5\u5165\u7535\u611f\u6216\u7535\u5bb9\u5143\u4ef6\u7684\u8bdd\uff0c\u7535\u6d41\u7535\u89d2\u5ea6\u5219\u4f1a\u6ede\u540e\u6216\u8d85\u524d\u3002
\u8fd9\u4e9b\u5176\u5b9e\u5982\u679c\u6709\u56fe\u5f62\u6765\u89e3\u91ca\u7684\u8bdd\u4f1a\u66f4\u597d\u89e3\u91ca\u70b9\uff0c\u5982\u679c\u4f60\u6709\u9700\u8981\u7684\u8bdd\u53ef\u4ee5\u8be6\u8c08\u3002
因为大家都知道电压的方向不在乎代表正电压和负电压两个方向,但现实生活中的电压量大小是成正弦波的波形来输出的,也就是同大小电压（这时是说的平均电压）下的同一时刻（此时间是说的是瞬间）电压是不一样的（对应在正弦波的不同波段中.）.所以为了区别不同的电压,电力上定义了一个电角度来区别不同的电压.
而此时电压如果接入纯电阻元件的话,电流电角度与电压电角度一样,而如果此电压接入电感或电容元件的话,电流电角度则会滞后或超前.
绛旓細鐢垫祦鐨勬柟鍚戞槸涓轰簡鏍规嵁鐢靛帇鐨勬柟鍚戣岀‘瀹氱殑.姝ゆ椂鐨勭數娴佹柟鍚戜笌鐢靛帇鏂瑰悜涓鏍锋槸涓轰簡鍖哄埆浜庝笉鍚岀數鍘,鑰屼笉鏄崟绾殑涓涓煝閲.鍥犱负澶у閮界煡閬撶數鍘嬬殑鏂瑰悜涓嶅湪涔庝唬琛ㄦ鐢靛帇鍜岃礋鐢靛帇涓や釜鏂瑰悜,浣嗙幇瀹炵敓娲讳腑鐨勭數鍘嬮噺澶у皬鏄垚姝ｅ鸡娉㈢殑娉㈠舰鏉ヨ緭鍑虹殑,涔熷氨鏄悓澶у皬鐢靛帇锛堣繖鏃舵槸璇寸殑骞冲潎鐢靛帇锛変笅鐨勫悓涓鏃跺埢锛堟鏃堕棿鏄鐨勬槸...
绛旓細鐢垫祦涓嶄粎鏈夊ぇ灏忥紝鑰屼笖鏈夋柟鍚戯紝鎴戜滑瑙勫畾鐢佃矾涓鐢佃嵎娴佸姩鐨勬柟鍚戜负鐢垫祦鐨勬柟鍚锛屽洜姝わ紝鐢垫祦涓嶅悓浜庝竴鑸殑鏍囬噺锛堝璐ㄩ噺銆佹俯搴︾瓑锛夈傜數娴佺殑鏂瑰悜浠呰〃绀轰竴绉嶅惧悜锛屽彧琛ㄧず鐢佃矾涓數鑽蜂粠鏌愬鍚戝彟涓澶勪綔椤烘椂閽堟垨閫嗘椂閽堟祦鍔ㄧ殑鍊惧悜锛屽苟涓嶈〃绀虹數璺腑鐢佃嵎娴佸姩鐨勭‘鍒囨柟鍚戯紝鐢佃嵎杩愬姩鐨勬柟鍚戣鐢ㄧ數娴佸瘑搴︾煝閲忔墠鑳界‘鍒囧湴琛ㄧず鍑烘潵銆
绛旓細浣犳墍璇寸殑鐢垫祦锛屽嵆鐢垫祦寮哄害銆傜數娴佸己搴︽槸鏍囬噺锛屼絾瀹冩湁鏂瑰悜銆備富瑕佽鏄庡涓嬶細涓銆佺數娴佺殑杩欎釜鏂瑰悜涓庣煝閲忕殑鏂瑰悜鍚箟涓嶅悓銆傞氬父鎵璇寸殑鐭㈤噺锛屽彲浠ユ湁鏃犻檺澶氫釜鍙兘鐨勬柟鍚戙備絾鐢垫祦鐨勬柟鍚戯紝鍙湁涓ょ鍙兘鐨勬柟鍚戙瑕佷箞鏄祦杩涙煇涓埅闈紝瑕佷箞鏄祦鍑烘煇涓埅闈銆備簩銆佺數娴佽繖涓爣閲忥紝涓庣數闃昏繖鏍风殑鏍囬噺涔熶笉鍚屻傜數闃绘槸鏃犳柟鍚戠殑绠...
绛旓細锛1锛夌數娴佹槸鏍囬噺銆傦紙2锛夌數娴佹湁鏂瑰悜銆佷絾鏄數娴佹槸鏍囬噺銆銆鍘熷洜锛氱數娴佺殑杩愮畻閬典粠浠ｆ暟杩愮畻銆傘姣斿骞惰仈鐢佃矾涓 I1=3A I2=4A 銆鐢佃矾鎬荤數娴 I=I1+I2=7A 鐩存帴鐩稿姞 鏄爣閲忋傘濡傛灉鏄煝閲 I=(I1^2+I2^2)^1/2=5A 涓嶇鍚堝苟鑱旂數璺湁鐗圭偣銆鎵浠ャ佺數娴佹槸鏍囬噺銆
绛旓細濡傛灉姝ゆ椂瀵肩嚎AB鍐呴儴鏈変袱涓笉鍚岀殑鐢垫祦锛屽畠浠殑鏂瑰悜鍙兘鐩稿悓锛岀洿鎺ョ浉鍔犲氨鍙互浜嗭紝褰撶劧涔熷彲鑳界浉鍙嶏紝灏卞彲浠ョ浉鍑忓氨鍙互浜嗐傝繖鏃朵篃鍙互绠鍗曠殑瑙勫畾鍏朵腑鐨勪竴涓柟鍚戜负姝ｆ柟鍚戯紝鍙﹀涓涓负璐燂紝灏卞彲浠ュ仛涓轰唬鏁伴噺鐩存帴杩涜璁＄畻锛岄潪甯告柟渚跨殑銆傞噸鍔涘娍鑳戒篃鏄爣閲忥紝涔熸湁姝ｈ礋涔嬪垎銆傚洜涓哄畠涓庨浂鍔胯兘鏈夊叧鐨勶紝鍦ㄩ浂鍔胯兘涔嬩笂鐨勪负...
绛旓細浜轰负鐨勪竴绉嶇害瀹氾細姝ｇ數鑽峰畾鍚戠Щ鍔ㄧ殑鏂瑰悜灏辨槸鐢垫祦鏂瑰悜銆傝屼笖鐢垫祦鐨勬柟鍚戝彂鐢熸敼鍙橈紝涔熶笉褰卞搷鐢垫祦鐨勬晥鏋滐紝姣斿锛氬湪涓茶仈鐢佃矾涓紝铏界劧瀵肩嚎寮集鏇叉洸锛屼絾鎴戜滑浠嶇劧璇粹滃湪涓茶仈鐢佃矾涓紝鐢垫祦澶勫鐩稿悓鈥濄傜敱姝ょ湅鏉ワ紝铏界劧鐢垫祦鐨勬柟鍚戦殢瀵肩嚎鐨勫集鏇茶屾敼鍙橈紝浣嗗苟涓嶅奖鍝嶇數娴佺殑鏁堟灉銆傛墍浠ユ妸鐢垫祦鐪嬩綔鏍囬噺銆傚弬鑰冭祫鏂欙細鐘跺厓绗旇 ...
绛旓細1mA=1000渭A 鐗╃悊涓婅瀹鐢垫祦鐨鏂瑰悜锛鏄鐢佃嵎瀹氬悜杩愬姩鐨勬柟鍚戯紙鍗虫鐢佃嵎瀹氬悜杩愬姩鐨勬柟鍚戯級銆傜數娴佽繍鍔ㄦ柟鍚戜笌鐢靛瓙杩愬姩鏂瑰悜鐩稿弽銆傜數鑽锋寚鐨勬槸鑷敱鐢佃嵎锛屽湪閲戝睘瀵间綋涓殑鑷敱鐢佃嵎鏄嚜鐢辩數瀛愶紝鍦ㄩ吀锛岀⒈锛岀洂鐨勬按婧舵恫涓槸姝ｇ瀛愬拰璐熺瀛愩傚笇鏈涙垜鑳藉府鍔╀綘瑙ｇ枒閲婃儜銆傚湪鐢垫簮澶栭儴鐢垫祦鐢辨鏋佹祦鍚戣礋鏋併傚湪鐢垫簮鍐呴儴鐢辫礋鏋佹祦...
绛旓細鐪熸鎰忎箟涓婄殑鏂瑰悜锛鍦ㄤ笁缁寸┖闂村潗鏍囦腑鏄敮涓鐨勩傛瘮濡傜珫鐩村悜涓娿佹按骞冲悜鍙崇瓑绛夈傜數鍘嬨佺數娴佺殑鏂瑰悜鏄寜鐓х數鍔跨殑楂樹綆銆佺數鑽风殑璧板悜瑙勫畾鐨勩傚绾挎棤璁烘庝箞鏀剧疆锛岀數鍘嬨鐢垫祦鏂瑰悜閮芥槸浠庝竴绔埌鍙︿竴绔紝璺熺┖闂存寚鍚戞棤鍏炽傛墍浠ョ數鍘嬬數娴佷笉灞炰簬鐭㈤噺鑰屽睘浜鏍囬噺銆
绛旓細鐢垫祦鐨勬柟鍚戞槸涓轰簡鏍规嵁鐢靛帇鐨勬柟鍚戣岀‘瀹氱殑銆傛鏃剁殑鐢垫祦鏂瑰悜涓庣數鍘嬫柟鍚戜竴鏍锋槸涓轰簡鍖哄埆浜庝笉鍚岀數鍘嬶紝鑰屼笉鏄崟绾殑涓涓煝閲忋傚洜涓哄ぇ瀹堕兘鐭ラ亾鐢靛帇鐨勬柟鍚戜笉鍦ㄤ箮浠ｈ〃姝ｇ數鍘嬪拰璐熺數鍘嬩袱涓柟鍚戯紝浣嗙幇瀹炵敓娲讳腑鐨勭數鍘嬮噺澶у皬鏄垚姝ｅ鸡娉㈢殑娉㈠舰鏉ヨ緭鍑虹殑锛屼篃灏辨槸鍚屽ぇ灏忕數鍘嬶紙杩欐椂鏄鐨勫钩鍧囩數鍘嬶級涓嬬殑鍚屼竴鏃跺埢锛堟鏃堕棿鏄...
绛旓細鍏跺疄涓ユ牸璇村洜涓鏈夋柟鍚戯紝涔熷氨鏄湁姝ｈ礋锛屽彲浠ヨ鏄煝閲忋備絾鏄敱浜鐢垫祦鐨勬柟鍚戝彧浼氭部鐫瀵肩嚎锛岃涔堝嚭锛岃涔堝叆锛屽氨鏄涔堟锛岃涔堣礋锛岃屼笉浼氳薄閫熷害閭ｆ牱鍙互鏄悇涓柟鍚戯紝鍙互鎴愯搴︾殑鏂瑰悜锛屽洜姝わ紝涔熷彲浠ヨ鏄爣閲銆
