Question

18£®ÈçͼËùʾµÄ±ÕºÏµç·£¬EÊǵçÔ´¡¢R₁ÊǶ¨Öµµç×è¡¢R₂ÊÇ»¬¶¯±ä×èÆ÷£¬CÊÇƽÐаåµçÈÝÆ÷£®³õʼʱ´øµçСÇòÇ¡ºÃ¾²Ö¹ÔÚƽÐаåµçÈÝÆ÷ÖУ®ÏÖÔÚ½«R₂µÄ»¬Æ¬´ÓÓÒÏò×óÔÈËÙ»¬¶¯£¬R₂µÄµç×èÊÇ´Öϸ¾ùÔȵĽðÊôÏßµç×裮v±íʾ´øµçСÇòËٶȣ¬U_C±íʾµçÈÝÆ÷¼«°åÖ®¼äµçѹ£¬q±íʾµçÈÝÆ÷¼«°åËù´øµçÁ¿£¬F±íʾ´øµçСÇòËùÊܵĵ糡Á¦£¬t±íʾʱ¼ä£¨´ÓR₂µÄ»¬Æ¬¿ªÊ¼»¬¶¯Ê±¼Æʱ£©£¬ÔòÏÂÁÐͼÏóÖÐÕýÈ·µÄÊÇ£¨¡¡¡¡£©

• A£®
• B£®
• C£®
• D£®

Answer 1

·ÖÎö ¸ù¾Ý±ÕºÏµç·ŷķ¶¨ÂÉÁÐʽÇó½â³öµç×èR₁µÄµçѹµÄ±í´ïʽ·ÖÎö£¬¸ù¾ÝÅ£¶ÙµÚ¶þ¶¨ÂÉ·ÖÎö¼ÓËÙ¶ÈÇé¿ö£¬¸ù¾ÝQ=CU·ÖÎöµçÈÝÆ÷´øµçÇé¿ö£¬¸ù¾ÝF=qE·ÖÎöµç³¡Á¦Çé¿ö£®

½â´ð ½â£ºC¡¢¸ù¾Ý±ÕºÏµç·ŷķ¶¨ÂÉ£¬ÓУº
${U}_{C}^{\;}=\frac{E}{{R}_{1}^{\;}+{R}_{2}^{\;}+r}{R}_{1}^{\;}$
¹Ê£º$\frac{1}{{U}_{C}^{\;}}=\frac{{R}_{1}^{\;}+r}{E{R}_{1}^{\;}}+\frac{1}{E{R}_{1}^{\;}}{R}_{2}^{\;}$¹Ê$\frac{1}{{U}_{C}^{\;}}$ÓëR₂ÊÇÏßÐÔ¹Øϵ£»
ÓÉÓÚ½«R₂µÄ»¬Æ¬ÔÈËÙÏò×󻬶¯£¬R₂µÄµç×èÊÇ´Öϸ¾ùÔȵĽðÊôÏßµç×裬¹ÊR₂Ëæ×Åʱ¼ä¾ùÔÈÔö¼Ó£¬¹Ê$\frac{1}{{U}_{C}^{\;}}$ÓëtÊÇÏßÐÔ¹Øϵ£¬¹ÊCÕýÈ·£»
A¡¢ÓÉÓÚU_CÊǼõСµÄ£¬¹Ê¼«°å¼äµÄ³¡Ç¿Ò²ÊǼõСµÄ£¬¹Êµç³¡Á¦ÊǼõСµÄ£¬¹Ê¼ÓËÙ¶ÈÊDZ仯µÄ£¬²»¿ÉÄÜÊÇÔȱäËÙÖ±ÏßÔ˶¯£¬¹ÊA´íÎó£»
B¡¢ÓÉÓÚ$\frac{1}{{U}_{C}^{\;}}$ÓëtÊÇÏßÐÔ¹Øϵ£¬¹ÊU_CÓëʱ¼ä²»ÊÇÏßÐÔ¹Øϵ£¬¸ù¾ÝQ=CU£¬µçÈÝÆ÷µÄ´øµçÁ¿Óëʱ¼ä²»ÊÇÏßÐÔ¹Øϵ£¬¹ÊB´íÎó£»
D¡¢¸ù¾ÝU=EdºÍF=qE£¬µç³¡Á¦ÓëU_CÊÇÏßÐÔ¹Øϵ£»¶øU_CÓëʱ¼ä²»ÊÇÏßÐÔ¹Øϵ£¬¹ÊFÓët²»ÊÇÏßÐÔ¹Øϵ£»¹ÊD´íÎó£»
¹ÊÑ¡£ºC£®

µãÆÀ ±¾Ìâ¹Ø¼üÊÇÍƵ¼³ö¸÷¸ö±í´ïʽ½øÐзÖÎö£¬Í¬Ê±Òª½áºÏÊýѧÖÐÒ»´Îº¯ÊýµÄ֪ʶ·ÖÎö£¬²»ÄÑ£®