// Numbas version: finer_feedback_settings
{"name": "EL Q002 Capacitors, Inductors & Step Response", "extensions": [], "custom_part_types": [], "resources": [["question-resources/SbE_CC1_Q4b.png", "/srv/numbas/media/question-resources/SbE_CC1_Q4b.png"], ["question-resources/EL_Q002c_-_Capacitor_Charge-Discharge.png", "/srv/numbas/media/question-resources/EL_Q002c_-_Capacitor_Charge-Discharge.png"], ["question-resources/EL_Q002a.v2_-_RC_Circuit.png", "/srv/numbas/media/question-resources/EL_Q002a.v2_-_RC_Circuit.png"]], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"name": "EL Q002 Capacitors, Inductors & Step Response", "tags": [], "metadata": {"description": "<p>Question covering Capacitors, Inductors &amp; Step Response</p>", "licence": "All rights reserved"}, "statement": "<h1 style=\"text-align: center;\">Capacitors, Inductors &amp; Step Response</h1>", "advice": "<p>See Spreadsheet</p>", "rulesets": {}, "extensions": [], "builtin_constants": {"e": true, "pi,\u03c0": true, "i": true, "j": false}, "constants": [], "variables": {"Q002b_L1": {"name": "Q002b_L1", "group": "EL Q002b", "definition": "random(0.05 .. 0.05#1)", "description": "<p>Solenoid Inductace (L<sub>1</sub>)</p>", "templateType": "randrange", "can_override": true}, "Q002b_R1": {"name": "Q002b_R1", "group": "EL Q002b", "definition": "random(1 .. 2#0.2)", "description": "<p>Solenoid Resistance (&Omega;)</p>", "templateType": "randrange", "can_override": false}, "Q002b_Solenoid_length": {"name": "Q002b_Solenoid_length", "group": "EL Q002b", "definition": "random(10 .. 10#1)", "description": "<p>The length (<em>l </em>) of the solenoid in mm</p>", "templateType": "randrange", "can_override": false}, "Q002b_Armature_Gap": {"name": "Q002b_Armature_Gap", "group": "EL Q002b", "definition": "random(2 .. 2#1)", "description": "<p>the gap (g) between the solenoid and the armature in mm&nbsp;</p>", "templateType": "randrange", "can_override": false}, "Q002b_F_gen": {"name": "Q002b_F_gen", "group": "EL Q002b", "definition": "random(2.3 .. 2.3#1)", "description": "<p>Force (F) generated by the solenoid in N</p>", "templateType": "randrange", "can_override": false}}, "variablesTest": {"condition": "", "maxRuns": 100}, "ungrouped_variables": [], "variable_groups": [{"name": "EL Q4a", "variables": []}, {"name": "EL Q002b", "variables": ["Q002b_L1", "Q002b_R1", "Q002b_Solenoid_length", "Q002b_Armature_Gap", "Q002b_F_gen"]}], "functions": {}, "preamble": {"js": "", "css": ""}, "parts": [{"type": "information", "useCustomName": false, "customName": "", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "<p><strong>Part a. Capacitor Properties</strong></p>\n<p>The diagram shows a capacitor and resistor in a Series DC circuit.&nbsp;</p>\n<p><img src=\"resources/question-resources/EL_Q002a.v2_-_RC_Circuit.png\" width=\"878\" height=\"362\"/></p>\n<ul>\n<li>State the function of a capacitor in a DC circuit.</li>\n<li>State the equation that relates the physical parameters of the capacitor.</li>\n<li>Give a definition of the time constant for this circuit.</li>\n</ul>\n<p><strong>[4 Marks]</strong></p>"}, {"type": "information", "useCustomName": false, "customName": "", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "<p><strong>Part b) Solenoid Calculation</strong></p>\n<p>The figure shows a solenoid electromagnet circuit compromising the inductance of the coil and the series resistance.&nbsp; It is being energised by a battery.&nbsp; The switch has been closed for {100*Q002b_L1*Q002b_R1}s.&nbsp;</p>\n<p><img src=\"resources/question-resources/SbE_CC1_Q4b.png\" alt=\"Solenoid Circuit &amp; Equations\" width=\"598\" height=\"405\" style=\"display: block; margin-left: auto; margin-right: auto;\"/></p>\n<p>The measured Inductance (<em>L</em>) of the solenoid is {siground(dec(Q002b_L1*1000),4)}mH and the Resistance is {Q002b_R1}&Omega;.&nbsp; The length (<em>l </em>) of the solenoid is {Q002b_Solenoid_length}mm and the gap (g) between the solenoid and the armature is {Q002b_Armature_Gap}mm.</p>\n<ul>\n<li>What is the current flowing in the inductor to generate a force of {Q002b_F_gen}N?</li>\n<li>For this current, what is the magnitude of the supply voltage V<sub>S</sub>?</li>\n</ul>\n<p><strong>SPICE circuit suitable for analysis: <a href=\"https://www.multisim.com/content/ZuzqgJDNgXqNmpNiGf6euc/foes-el-q002b/open/\" target=\"_blank\" rel=\"noopener\">FoES El Q002b</a></strong></p>\n<p><strong>[6Marks]</strong></p>\n<p></p>\n<p></p>"}, {"type": "information", "useCustomName": false, "customName": "", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "<p><strong>Part c. Step Response</strong></p>\n<p>The circuit shows a Resistor and Capacitor Network as well as the charge/discharge plots of the Capacitor when the switch is closed and opened.</p>\n<p><img src=\"resources/question-resources/EL_Q002c_-_Capacitor_Charge-Discharge.png\" width=\"1524\" height=\"469\"/></p>\n<p>V<sub>S</sub> = {5} V, V<sub>B</sub> = {2.5} V t<sub>ON </sub>={50} ms, t<sub>OFF </sub>={200} ms C<sub>1</sub> ={10} &mu;F , R<sub>1</sub> = {10} k&Omega;, R<sub>2</sub> = {2} k&Omega;</p>\n<p>&nbsp;</p>\n<p>Explain what is happening in the circuit.&nbsp; What is the relationship between the voltage across and current through the Capacitor.</p>\n<p>SPICE circuit suitable for analysis: <a href=\"https://www.multisim.com/content/9rW4rVU7peuxbZD6f2JvAk/foes-q002c/open/\" target=\"_blank\" rel=\"noopener\">FoES Q002c</a></p>\n<p><strong>[10 Marks]</strong></p>\n<p></p>\n<p></p>\n<p></p>"}, {"type": "extension", "useCustomName": false, "customName": "", "marks": 1, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null}], "partsMode": "all", "maxMarks": 0, "objectives": [], "penalties": [], "objectiveVisibility": "always", "penaltyVisibility": "always", "contributors": [{"name": "Robert Bauld", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/19446/"}]}]}], "contributors": [{"name": "Robert Bauld", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/19446/"}]}