{"group":{"id":1,"name":"Community","lockable":false,"created_at":"2012-01-18T18:02:15.000Z","updated_at":"2026-05-26T00:16:20.000Z","description":"Problems submitted by members of the MATLAB Central community.","is_default":true,"created_by":161519,"badge_id":null,"featured":false,"trending":false,"solution_count_in_trending_period":0,"trending_last_calculated":"2026-05-26T00:00:00.000Z","image_id":null,"published":true,"community_created":false,"status_id":2,"is_default_group_for_player":false,"deleted_by":null,"deleted_at":null,"restored_by":null,"restored_at":null,"description_opc":null,"description_html":null,"published_at":null},"problems":[{"id":453,"title":"resistor ladder","description":"* You have a bunch (an odd number N) of identical resistors (each R ohms), a good battery (V volts), and a high impedance voltmeter. \r\n* Create a ladder as follows. \r\n* Connect negative terminal of the battery to ground. \r\n* Connect positive terminal of the battery to one resistor. Connect other end of this resistor to two resistors. \r\n* Connect other end of the second resistor to ground. Connect other end of the third resistor to two resistors and keep building similarly as long as possible.\r\n* Connect the last end of the last resistor to the voltmeter and measure the reading with reference to ground. \r\n* Please give the general solution. The test suite may change.   ","description_html":"\u003cul\u003e\u003cli\u003eYou have a bunch (an odd number N) of identical resistors (each R ohms), a good battery (V volts), and a high impedance voltmeter.\u003c/li\u003e\u003cli\u003eCreate a ladder as follows.\u003c/li\u003e\u003cli\u003eConnect negative terminal of the battery to ground.\u003c/li\u003e\u003cli\u003eConnect positive terminal of the battery to one resistor. Connect other end of this resistor to two resistors.\u003c/li\u003e\u003cli\u003eConnect other end of the second resistor to ground. Connect other end of the third resistor to two resistors and keep building similarly as long as possible.\u003c/li\u003e\u003cli\u003eConnect the last end of the last resistor to the voltmeter and measure the reading with reference to ground.\u003c/li\u003e\u003cli\u003ePlease give the general solution. The test suite may change.\u003c/li\u003e\u003c/ul\u003e","function_template":"function reading = ladder(N,R,V)\r\n  reading=V/N/R;\r\nend","test_suite":"%%\r\nN=3; R=100; V=12;\r\nreading_correct = 6;\r\nreading = ladder(N,R,V);\r\nassert(abs(reading-reading_correct)\u003c1000*eps)\r\n%%\r\nN=3; R=100; V=120;\r\nreading_correct = 60;\r\nreading = ladder(N,R,V);\r\nassert(abs(reading-reading_correct)\u003c1000*eps)\r\n%%\r\nN=5; R=100; V=100;\r\nreading_correct = 20;\r\nreading = ladder(N,R,V);\r\nassert(abs(reading-reading_correct)\u003c1000*eps)\r\n%%\r\n","published":true,"deleted":false,"likes_count":0,"comments_count":0,"created_by":166,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":34,"test_suite_updated_at":"2012-03-24T05:41:51.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2012-03-06T03:06:51.000Z","updated_at":"2025-05-16T15:09:44.000Z","published_at":"2012-03-06T03:10:07.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"targetMode\":\"\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"targetMode\":\"\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\\n\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eYou have a bunch (an odd number N) of identical resistors (each R ohms), a good battery (V volts), and a high impedance voltmeter.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eCreate a ladder as follows.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eConnect negative terminal of the battery to ground.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eConnect positive terminal of the battery to one resistor. Connect other end of this resistor to two resistors.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eConnect other end of the second resistor to ground. Connect other end of the third resistor to two resistors and keep building similarly as long as possible.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eConnect the last end of the last resistor to the voltmeter and measure the reading with reference to ground.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003ePlease give the general solution. The test suite may change.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"}],"problem_search":{"problems":[{"id":453,"title":"resistor ladder","description":"* You have a bunch (an odd number N) of identical resistors (each R ohms), a good battery (V volts), and a high impedance voltmeter. \r\n* Create a ladder as follows. \r\n* Connect negative terminal of the battery to ground. \r\n* Connect positive terminal of the battery to one resistor. Connect other end of this resistor to two resistors. \r\n* Connect other end of the second resistor to ground. Connect other end of the third resistor to two resistors and keep building similarly as long as possible.\r\n* Connect the last end of the last resistor to the voltmeter and measure the reading with reference to ground. \r\n* Please give the general solution. The test suite may change.   ","description_html":"\u003cul\u003e\u003cli\u003eYou have a bunch (an odd number N) of identical resistors (each R ohms), a good battery (V volts), and a high impedance voltmeter.\u003c/li\u003e\u003cli\u003eCreate a ladder as follows.\u003c/li\u003e\u003cli\u003eConnect negative terminal of the battery to ground.\u003c/li\u003e\u003cli\u003eConnect positive terminal of the battery to one resistor. Connect other end of this resistor to two resistors.\u003c/li\u003e\u003cli\u003eConnect other end of the second resistor to ground. Connect other end of the third resistor to two resistors and keep building similarly as long as possible.\u003c/li\u003e\u003cli\u003eConnect the last end of the last resistor to the voltmeter and measure the reading with reference to ground.\u003c/li\u003e\u003cli\u003ePlease give the general solution. The test suite may change.\u003c/li\u003e\u003c/ul\u003e","function_template":"function reading = ladder(N,R,V)\r\n  reading=V/N/R;\r\nend","test_suite":"%%\r\nN=3; R=100; V=12;\r\nreading_correct = 6;\r\nreading = ladder(N,R,V);\r\nassert(abs(reading-reading_correct)\u003c1000*eps)\r\n%%\r\nN=3; R=100; V=120;\r\nreading_correct = 60;\r\nreading = ladder(N,R,V);\r\nassert(abs(reading-reading_correct)\u003c1000*eps)\r\n%%\r\nN=5; R=100; V=100;\r\nreading_correct = 20;\r\nreading = ladder(N,R,V);\r\nassert(abs(reading-reading_correct)\u003c1000*eps)\r\n%%\r\n","published":true,"deleted":false,"likes_count":0,"comments_count":0,"created_by":166,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":34,"test_suite_updated_at":"2012-03-24T05:41:51.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2012-03-06T03:06:51.000Z","updated_at":"2025-05-16T15:09:44.000Z","published_at":"2012-03-06T03:10:07.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"targetMode\":\"\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"targetMode\":\"\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\\n\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eYou have a bunch (an odd number N) of identical resistors (each R ohms), a good battery (V volts), and a high impedance voltmeter.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eCreate a ladder as follows.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eConnect negative terminal of the battery to ground.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eConnect positive terminal of the battery to one resistor. Connect other end of this resistor to two resistors.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eConnect other end of the second resistor to ground. Connect other end of the third resistor to two resistors and keep building similarly as long as possible.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eConnect the last end of the last resistor to the voltmeter and measure the reading with reference to ground.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003ePlease give the general solution. The test suite may change.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"}],"errors":[],"facets":[[],[{"value":"medium","count":1,"selected":false}]],"term":"tag:\"network\"","page":1,"per_page":50,"sort":"map(difficulty_value,0,0,999) asc"}}