{"id":360,"date":"2020-04-15T22:17:52","date_gmt":"2020-04-15T22:17:52","guid":{"rendered":"https:\/\/wp.physics.wisc.edu\/ingersollmuseum\/?page_id=360"},"modified":"2026-05-11T05:33:23","modified_gmt":"2026-05-11T05:33:23","slug":"circuitpuzzle1","status":"publish","type":"page","link":"https:\/\/wp.physics.wisc.edu\/ingersollmuseum\/exhibits\/em\/circuitpuzzle1\/","title":{"rendered":"Circuit Puzzle 1"},"content":{"rendered":"

Circuit Puzzle 1<\/h1>\n\n\n
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\"\"<\/figure>\n\n\n\n

On the board below is a drawing representing the circuit inside the box connecting the switches and light bulbs.<\/p>\n\n\n\n

Wires<\/u><\/strong> are shown by LINES<\/strong>. Switches are shown by ANGLED LINES<\/strong>. \"\"<\/p>\n\n\n\n

Light bulbs<\/u><\/strong> are represented at their location in the circuit by CIRCLES<\/strong>. \"\"<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

Things to keep in mind when trying to accomplish the tasks:<\/u><\/strong><\/p>\n\n\n\n

When a switch is open (OFF\/ down) no electrons flow through that section of wire (no current<\/strong>).<\/p>\n\n\n\n

Light bulbs have resistance <\/strong>to flowing charges, so the more of them there are (or the longer the section of wire, which also has some resistance), the dimmer the lights will be since less power will be available for the light bulbs. See the Series\/Parallel Circuit Exhibit<\/em> for another circuit puzzle!<\/p>\n\n\n\n

Try to accomplish the following tasks by flipping the switches!!<\/strong><\/p>\n\n\n\n

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  1. FLIP THE SWITCHES TO GET LIGHTS A AND C TO TURN ON, BUT NOT B.<\/strong>\n
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    1. ANSWER: SW1<\/strong> UP, SW2<\/strong> UP, SW3<\/strong> UP, SW4<\/strong> DOWN, SW5<\/strong> UP, SW6<\/strong> DOWN<\/li>\n<\/ol>\n<\/li>\n\n\n\n
    2. FLIP THE SWITCHES TO GET JUST LIGHT B TO TURN ON.<\/strong>\n
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      1. ANSWER: SW1<\/strong> UP, SW2<\/strong> DOWN, SW3<\/strong> UP, SW4<\/strong> UP, SW5<\/strong> DOWN, SW6<\/strong> DOWN<\/li>\n<\/ol>\n<\/li>\n\n\n\n
      2. FLIP THE SWITCHES TO GET JUST LIGHTS B AND C TO TURN ON.<\/strong>\n
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        1. ANSWER 2 (dim): SW1<\/strong> UP, SW2<\/strong> DOWN, SW3<\/strong> DOWN, SW4<\/strong> DOWN, SW5<\/strong> DOWN, SW6<\/strong> DOWN<\/li>\n\n\n\n
        2. ANSWER 2 (bright): SW1<\/strong> UP, SW2<\/strong> DOWN, SW3<\/strong> UP, SW4<\/strong> UP, SW5<\/strong> UP, SW6<\/strong> DOWN<\/li>\n<\/ol>\n<\/li>\n\n\n\n
        3. FLIP THE SWITCHES TO GET ALL THREE LIGHTS TO TURN ON.<\/strong>\n
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          1. ANSWER1 (dim): SW1<\/strong> UP, SW2<\/strong> UP, SW3<\/strong> UP, SW4<\/strong> DOWN, SW5<\/strong> DOWN, SW6<\/strong> DOWN<\/li>\n\n\n\n
          2. ANSWER2 (bright): SW1<\/strong> UP, SW2<\/strong> UP, SW3<\/strong> UP, SW4<\/strong> UP, SW5<\/strong> UP, SW6<\/strong> DOWN<\/li>\n<\/ol>\n<\/li>\n<\/ol>\n\n\n\n

            V=IR   There is a set voltage from the battery so more resistance (longer wire or more lightbulbs) = less current<\/p>\n\n\n\n

            P=IV=I2<\/sup>R   Current gets split between each available path.  The amount of current in each path depends on the resistance of that path.  All the same light bulbs, so all have same resistance, but the current available depends on how much current is flowing through each section of wire.<\/p>\n\n\n\n

             <\/p>\n\n\n\n

            Other Combinations:<\/strong><\/p>\n\n\n\n

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            1. JUST Bulb “A”\n
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              1. ANSWER: SW1<\/strong> UP, SW2<\/strong> UP, SW3<\/strong> UP, SW4<\/strong> DOWN, SW5<\/strong> DOWN, SW6<\/strong> UP<\/li>\n<\/ol>\n<\/li>\n\n\n\n
              2. All lights off\n
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                1. ANSWER 1: SW1<\/strong> DOWN, others don\u2019t matter since no current in circuit<\/li>\n\n\n\n
                2. ANSWER 2: SW1<\/strong> UP, SW2<\/strong> DOWN, SW3<\/strong> DOWN, SW4<\/strong> DOWN or UP, SW5<\/strong> DOWN or UP, SW6<\/strong> UP<\/li>\n\n\n\n
                3. ANSWER 3: SW1<\/strong> UP, SW2<\/strong> UP, SW3<\/strong> DOWN, SW4<\/strong> DOWN, SW5<\/strong> DOWN or UP, SW6<\/strong> UP<\/li>\n<\/ol>\n<\/li>\n\n\n\n
                4. Just Bulb “C”\n
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                  1. ANSWER 2: SW1<\/strong> UP, SW2<\/strong> UP, SW3<\/strong> DOWN, SW4<\/strong> DOWN or UP, SW5<\/strong> UP, SW6<\/strong> UP<\/li>\n<\/ol>\n<\/li>\n<\/ol>\n\n\n\n

                     <\/span><\/p>\n\n\n\n

                    Physics Lecture Demonstration Database<\/a><\/b><\/i><\/p>\n\n\n\n