A balanced, three phase, {VLINE} V system is supplying a load connected in {type}.
\n{image('resources/question-resources/'+Circuit)}
\n\nThe loads are:
\n$Z_1 = \\var{R1}+i\\ \\var{X1}\\ \\Omega $
\n$Z_2 = \\var{R2}+i\\ \\var{X2}\\ \\Omega $
\n$Z_3 = \\var{R3}+i\\ \\var{X3}\\ \\Omega $
\n\n\n", "advice": "", "rulesets": {}, "variables": {"R3": {"name": "R3", "group": "Impedances", "definition": "random(0 .. 100#1)", "description": "", "templateType": "randrange"}, "R2": {"name": "R2", "group": "Impedances", "definition": "random(0 .. 100#1)", "description": "", "templateType": "randrange"}, "VLINE": {"name": "VLINE", "group": "Voltages", "definition": "random(50 .. 1000#50)", "description": "Rated Voltage
", "templateType": "randrange"}, "R1": {"name": "R1", "group": "Impedances", "definition": "random(0 .. 100#1)", "description": "", "templateType": "randrange"}, "X1": {"name": "X1", "group": "Impedances", "definition": "random(0 .. 100#1)", "description": "", "templateType": "randrange"}, "X2": {"name": "X2", "group": "Impedances", "definition": "random(0 .. 100#1)", "description": "", "templateType": "randrange"}, "X3": {"name": "X3", "group": "Impedances", "definition": "random(0 .. 100#1)", "description": "", "templateType": "randrange"}, "VPH": {"name": "VPH", "group": "Voltages", "definition": "VLINE/sqrt(3)", "description": "Phase Voltage
", "templateType": "anything"}, "type": {"name": "type", "group": "System Type", "definition": "types[StarorDelta]", "description": "", "templateType": "anything"}, "types": {"name": "types", "group": "System Type", "definition": "[ \"star with a neutral\", \"delta\" ]", "description": "", "templateType": "list of strings"}, "StarorDelta": {"name": "StarorDelta", "group": "System Type", "definition": "random(0 .. 1#1)", "description": "index for the connection type:
\n0 = star with a neutral
\n1 = delta
", "templateType": "randrange"}, "Voltages": {"name": "Voltages", "group": "Voltages", "definition": "[VPH,VLINE]", "description": "", "templateType": "anything"}, "IA": {"name": "IA", "group": "Currents", "definition": "(1-StarorDelta)*I1 + StarorDelta*(I3-I2)", "description": "Line Current
", "templateType": "anything"}, "IB": {"name": "IB", "group": "Currents", "definition": "(1-StarorDelta)*I2 + StarorDelta*(I1-I3)", "description": "Line Current
", "templateType": "anything"}, "IC": {"name": "IC", "group": "Currents", "definition": "(1-StarorDelta)*I3 + StarorDelta*(I2-I1)", "description": "Line Current
", "templateType": "anything"}, "Neutral": {"name": "Neutral", "group": "Currents", "definition": "abs(IA+IB+IC)", "description": "", "templateType": "anything"}, "I1": {"name": "I1", "group": "Currents", "definition": "V1/(R1+X1*i)", "description": "Load Current
", "templateType": "anything"}, "I2": {"name": "I2", "group": "Currents", "definition": "V2/(R2+X2*i)", "description": "Load Current
", "templateType": "anything"}, "I3": {"name": "I3", "group": "Currents", "definition": "V3/(R3+X3*i)", "description": "Load Current
", "templateType": "anything"}, "Diagrams": {"name": "Diagrams", "group": "System Type", "definition": "['StarCircuit_zxgxKjR.png','DeltaCircuit_NBsNnJk.png']", "description": "", "templateType": "anything"}, "Circuit": {"name": "Circuit", "group": "System Type", "definition": "Diagrams[StarorDelta]", "description": "", "templateType": "anything"}, "PA": {"name": "PA", "group": "Power", "definition": "re(conj(IA)*VA)", "description": "", "templateType": "anything"}, "V1": {"name": "V1", "group": "Voltages", "definition": "(1-StarorDelta)*VA + StarorDelta*(VB-VC)", "description": "", "templateType": "anything"}, "V2": {"name": "V2", "group": "Voltages", "definition": "(1-StarorDelta)*VB + StarorDelta*(VC-VA)", "description": "", "templateType": "anything"}, "V3": {"name": "V3", "group": "Voltages", "definition": "(1-StarorDelta)*VC + StarorDelta*(VA-VB)", "description": "", "templateType": "anything"}, "VA": {"name": "VA", "group": "Voltages", "definition": "VPH*(cos(0)+i*sin(0))", "description": "", "templateType": "anything"}, "VB": {"name": "VB", "group": "Voltages", "definition": "VPH*(cos(-2*pi/3)+i*sin(-2*pi/3))", "description": "", "templateType": "anything"}, "VC": {"name": "VC", "group": "Voltages", "definition": "VPH*(cos(2*pi/3)+i*sin(2*pi/3))", "description": "", "templateType": "anything"}, "PB": {"name": "PB", "group": "Power", "definition": "re(conj(IB)*VB)", "description": "", "templateType": "anything"}, "PC": {"name": "PC", "group": "Power", "definition": "re(conj(IC)*VC)", "description": "", "templateType": "anything"}, "P1": {"name": "P1", "group": "Power", "definition": "re(conj(I1)*V1)", "description": "", "templateType": "anything"}, "P2": {"name": "P2", "group": "Power", "definition": "re(conj(I2)*V2)", "description": "", "templateType": "anything"}, "P3": {"name": "P3", "group": "Power", "definition": "re(conj(I3)*V3)", "description": "", "templateType": "anything"}, "PLine": {"name": "PLine", "group": "Power", "definition": "PA+PB+PC", "description": "", "templateType": "anything"}, "PLoad": {"name": "PLoad", "group": "Power", "definition": "P1+P2+P3", "description": "", "templateType": "anything"}, "I1angle": {"name": "I1angle", "group": "Currents", "definition": "180*arg(I1)/pi", "description": "", "templateType": "anything"}, "I2angle": {"name": "I2angle", "group": "Currents", "definition": "180*arg(I2)/pi", "description": "", "templateType": "anything"}, "I3angle": {"name": "I3angle", "group": "Currents", "definition": "180*arg(I3)/pi", "description": "", "templateType": "anything"}, "IAangle": {"name": "IAangle", "group": "Currents", "definition": "180*arg(IA)/pi", "description": "", "templateType": "anything"}, "IBangle": {"name": "IBangle", "group": "Currents", "definition": "180*arg(IB)/pi", "description": "", "templateType": "anything"}, "ICangle": {"name": "ICangle", "group": "Currents", "definition": "180*arg(IC)/pi", "description": "", "templateType": "anything"}}, "variablesTest": {"condition": "", "maxRuns": 100}, "ungrouped_variables": [], "variable_groups": [{"name": "Voltages", "variables": ["VLINE", "VPH", "Voltages", "VA", "VB", "VC", "V1", "V2", "V3"]}, {"name": "Impedances", "variables": ["R1", "R2", "R3", "X1", "X2", "X3"]}, {"name": "Currents", "variables": ["I1", "I2", "I3", "IA", "IB", "IC", "Neutral", "I1angle", "I2angle", "I3angle", "IAangle", "IBangle", "ICangle"]}, {"name": "Power", "variables": ["PA", "PB", "PC", "P1", "P2", "P3", "PLine", "PLoad"]}, {"name": "System Type", "variables": ["StarorDelta", "type", "types", "Circuit", "Diagrams"]}], "functions": {}, "preamble": {"js": "", "css": ""}, "parts": [{"type": "gapfill", "useCustomName": true, "customName": "Load Currents", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "What is the load voltage? [[0]] V
\nUsing $V_A$ as the reference voltage, calculate the currents in each load:
\n$I_1 = $[[1]]$\\angle$ [[2]]$^o$ A
\n$I_2 = $[[3]]$\\angle$ [[4]]$^o$ A
\n$I_3 = $[[5]]$\\angle$ [[6]]$^o$ A
", "stepsPenalty": 0, "steps": [{"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": "Determine the currents in each line:
\n$I_A = $[[0]]$\\angle$ [[1]]$^o$ A
\n$I_B = $[[2]]$\\angle$ [[3]]$^o$ A
\n$I_C = $[[4]]$\\angle$ [[5]]$^o$ A
", "stepsPenalty": 0, "steps": [{"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": "Determine the real power flowing in each line:
\n$P_A = $[[0]]W
\n$P_B = $[[1]]W
\n$P_C = $[[2]]W
", "stepsPenalty": 0, "steps": [{"type": "information", "useCustomName": false, "customName": "", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "Determine the real power flowing in each load:
\n$P_1 = $[[0]]W
\n$P_2 = $[[1]]W
\n$P_3 = $[[2]]W
", "stepsPenalty": 0, "steps": [{"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": "In the system shown in Figure 1, the transformers are connected star-star with both star points grounded and the generator is connected in star with its star points grounded. The per unit impedances of each element on a {SBASE} MVA base are given in Table 1 and the voltage levels are given in Table 2.
\n{image('resources/question-resources/PSScircuit.png')}
\nFigure 1: A section of the distribution system
\n| \n \n | \n\n Generator \n | \n\n Transformer T1 \n | \n\n Line \n | \n\n Transformer T2 \n | \n
| \n Z [p.u.] \n | \n\n {RG} + j {XG} \n | \n\n {RT1} + j {XT1} \n | \n\n {RL} + j {XL} \n | \n\n {RT2} + j {XT2} \n | \n
Table 1: Sequence impedances (p.u. on {SBASE} MVA base)
\n\n
| \n \n | \n\n Generator \n | \n\n Line \n | \n\n Load \n | \n
| \n V BASE [kV] \n | \n\n {VG} \n | \n\n {VLine} \n | \n\n {VLoad} \n | \n
Table 2: Voltage bases (kV)
", "advice": "", "rulesets": {}, "builtin_constants": {"e": true, "pi,\u03c0": true, "i": true}, "constants": [], "variables": {"XG": {"name": "XG", "group": "Ungrouped variables", "definition": "random(0.05 .. 0.1#0.01)", "description": "", "templateType": "randrange", "can_override": false}, "XL": {"name": "XL", "group": "Ungrouped variables", "definition": "random(0.05 .. 0.1#0.01)", "description": "", "templateType": "randrange", "can_override": false}, "XT1": {"name": "XT1", "group": "Ungrouped variables", "definition": "random(0.05 .. 0.2#0.01)", "description": "", "templateType": "randrange", "can_override": false}, "SBASE": {"name": "SBASE", "group": "Ungrouped variables", "definition": "random(10 .. 100#10)", "description": "", "templateType": "randrange", "can_override": false}, "IkA": {"name": "IkA", "group": "Calculated", "definition": "precround(Ipu*IBASE,3)", "description": "", "templateType": "anything", "can_override": false}, "XT2": {"name": "XT2", "group": "Ungrouped variables", "definition": "random(0.05 .. 0.1#0.01)", "description": "", "templateType": "randrange", "can_override": false}, "V1": {"name": "V1", "group": "Calculated", "definition": "1-(RG+i*XG)*IL", "description": "", "templateType": "anything", "can_override": false}, "V2": {"name": "V2", "group": "Calculated", "definition": "V1-(RT1+i*XT1)*IL", "description": "", "templateType": "anything", "can_override": false}, "V3": {"name": "V3", "group": "Calculated", "definition": "V2-(RL+i*XL)*IL", "description": "", "templateType": "anything", "can_override": false}, "V4": {"name": "V4", "group": "Calculated", "definition": "V3-(RT2+i*XT2)*IL", "description": "", "templateType": "anything", "can_override": false}, "delta1": {"name": "delta1", "group": "Calculated", "definition": "180*arg(V1)/pi", "description": "", "templateType": "anything", "can_override": false}, "delta2": {"name": "delta2", "group": "Calculated", "definition": "180*arg(V2)/pi", "description": "", "templateType": "anything", "can_override": false}, "delta3": {"name": "delta3", "group": "Calculated", "definition": "180*arg(V3)/pi", "description": "", "templateType": "anything", "can_override": false}, "RG": {"name": "RG", "group": "Ungrouped variables", "definition": "random(0.01 .. 0.04#0.01)", "description": "", "templateType": "randrange", "can_override": false}, "RT1": {"name": "RT1", "group": "Ungrouped variables", "definition": "random(0.01 .. 0.04#0.01)", "description": "", "templateType": "randrange", "can_override": false}, "RL": {"name": "RL", "group": "Ungrouped variables", "definition": "random(0.01 .. 0.04#0.01)", "description": "", "templateType": "randrange", "can_override": false}, "RT2": {"name": "RT2", "group": "Ungrouped variables", "definition": "random(0.01 .. 0.04#0.01)", "description": "", "templateType": "randrange", "can_override": false}, "VG": {"name": "VG", "group": "Ungrouped variables", "definition": "random(1 .. 9#1)", "description": "", "templateType": "randrange", "can_override": false}, "Vline": {"name": "Vline", "group": "Ungrouped variables", "definition": "random(5 .. 50#5)", "description": "", "templateType": "randrange", "can_override": false}, "Vload": {"name": "Vload", "group": "Ungrouped variables", "definition": "random(1 .. 9#1)", "description": "", "templateType": "randrange", "can_override": false}, "IBASE": {"name": "IBASE", "group": "Calculated", "definition": "SBASE/(sqrt(3)*VLoad)", "description": "", "templateType": "anything", "can_override": false}, "Ipu": {"name": "Ipu", "group": "Calculated", "definition": "random(0.1 .. 0.9#0.01)", "description": "percentage of full load on bus 4
", "templateType": "randrange", "can_override": false}, "loading": {"name": "loading", "group": "Calculated", "definition": "IkA/IBASE", "description": "", "templateType": "anything", "can_override": false}, "theta_rad": {"name": "theta_rad", "group": "Calculated", "definition": "-arccos(pf/100)", "description": "", "templateType": "anything", "can_override": false}, "pf": {"name": "pf", "group": "Ungrouped variables", "definition": "random(86 .. 99#2)", "description": "", "templateType": "randrange", "can_override": false}, "theta": {"name": "theta", "group": "Calculated", "definition": "180*theta_rad/pi", "description": "", "templateType": "anything", "can_override": false}, "IL": {"name": "IL", "group": "Calculated", "definition": "Ipu*cos(theta_rad)+i*Ipu*sin(theta_rad)", "description": "", "templateType": "anything", "can_override": false}, "delta4": {"name": "delta4", "group": "Calculated", "definition": "180*arg(V4)/pi", "description": "", "templateType": "anything", "can_override": false}, "V1m": {"name": "V1m", "group": "Calculated", "definition": "abs(V1)", "description": "", "templateType": "anything", "can_override": false}, "V4m": {"name": "V4m", "group": "Calculated", "definition": "abs(V4)", "description": "", "templateType": "anything", "can_override": false}, "V2m": {"name": "V2m", "group": "Calculated", "definition": "abs(V2)", "description": "", "templateType": "anything", "can_override": false}, "V3m": {"name": "V3m", "group": "Calculated", "definition": "abs(V3)", "description": "", "templateType": "anything", "can_override": false}, "P1": {"name": "P1", "group": "Calculated", "definition": "re(SBASE*1*conj(IL))", "description": "", "templateType": "anything", "can_override": false}, "P4": {"name": "P4", "group": "Calculated", "definition": "re(SBASE*V4*conj(IL))", "description": "", "templateType": "anything", "can_override": false}, "efficiency": {"name": "efficiency", "group": "Calculated", "definition": "100*P4/P1", "description": "", "templateType": "anything", "can_override": false}}, "variablesTest": {"condition": "", "maxRuns": 100}, "ungrouped_variables": ["XG", "RG", "XT1", "RT1", "XL", "RL", "XT2", "RT2", "VG", "Vline", "Vload", "SBASE", "pf"], "variable_groups": [{"name": "Calculated", "variables": ["IkA", "V1", "V2", "V3", "V4", "delta1", "delta2", "delta3", "delta4", "IBASE", "Ipu", "loading", "theta_rad", "theta", "IL", "V1m", "V2m", "V3m", "V4m", "P1", "P4", "efficiency"]}], "functions": {}, "preamble": {"js": "", "css": ""}, "parts": [{"type": "gapfill", "useCustomName": true, "customName": "Load Current", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "A load current of {IkA} kA is flowing with a lagging power factor of {pf} %. Convert this to a current vector in per-unit.
\n$ I_L $ = [[0]]$\\angle$ [[1]]$^o $ p.u.
", "gaps": [{"type": "numberentry", "useCustomName": true, "customName": "Ipu", "marks": "4", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minValue": "0.99*Ipu", "maxValue": "1.01*Ipu", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "displayAnswer": "", "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}, {"type": "numberentry", "useCustomName": true, "customName": "theta", "marks": "4", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minValue": "0.99*theta", "maxValue": "1.01*theta", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "displayAnswer": "", "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}], "sortAnswers": false}, {"type": "gapfill", "useCustomName": true, "customName": "Voltages", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "What are the voltages on bus (in p.u.)?
\n$ V_1 $ = [[0]]$\\angle$ [[1]]$^o$ p.u.
\n$ V_2 $ = [[2]]$\\angle$ [[3]]$^o$ p.u.
\n$ V_3 $ = [[4]]$\\angle$ [[5]]$^o$ p.u.
\n$ V_4 $ = [[6]]$\\angle$ [[7]]$^o$ p.u.
", "gaps": [{"type": "numberentry", "useCustomName": true, "customName": "V1", "marks": "1.5", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minValue": "0.99*V1m", "maxValue": "1.01*V1m", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "displayAnswer": "", "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}, {"type": "numberentry", "useCustomName": true, "customName": "delta1", "marks": "1.5", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minValue": "0.99*delta1", "maxValue": "1.01*delta1", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "displayAnswer": "", "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}, {"type": "numberentry", "useCustomName": true, "customName": "V2", "marks": "1.5", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minValue": "0.99*V2m", "maxValue": "1.01*V2m", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "displayAnswer": "", "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}, {"type": "numberentry", "useCustomName": true, "customName": "delta2", "marks": "1.5", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minValue": "0.99*delta2", "maxValue": "1.01*delta2", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "displayAnswer": "", "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}, {"type": "numberentry", "useCustomName": true, "customName": "V3", "marks": "1.5", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minValue": "0.99*V3m", "maxValue": "1.01*V3m", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "displayAnswer": "", "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}, {"type": "numberentry", "useCustomName": true, "customName": "delta3", "marks": "1.5", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minValue": "0.99*delta3", "maxValue": "1.01*delta3", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "displayAnswer": "", "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}, {"type": "numberentry", "useCustomName": true, "customName": "V4", "marks": "1.5", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minValue": "0.99*V4m", "maxValue": "1.01*V4m", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "displayAnswer": "", "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}, {"type": "numberentry", "useCustomName": true, "customName": "delta4", "marks": "1.5", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minValue": "0.99*delta4", "maxValue": "1.01*delta4", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "displayAnswer": "", "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}], "sortAnswers": false}, {"type": "gapfill", "useCustomName": true, "customName": "Efficiency", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "Calcuate the load power out in MW.
\n$ P_{OUT} $ = [[0]] MW
\nCalcuate the input power to the generator in MW.
\n$ P_{IN} $ = [[1]] MW
\nCalculate the overall efficiency of the sytem.
\n$ \\eta $ = [[2]] %
", "gaps": [{"type": "numberentry", "useCustomName": true, "customName": "P4", "marks": "4", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minValue": "0.99*P4", "maxValue": "1.01*P4", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "displayAnswer": "", "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}, {"type": "numberentry", "useCustomName": true, "customName": "P1", "marks": "4", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minValue": "0.99*P1", "maxValue": "1.01*P1", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "displayAnswer": "", "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}, {"type": "numberentry", "useCustomName": true, "customName": "efficiency", "marks": "2", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minValue": "0.99*efficiency", "maxValue": "1.01*efficiency", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "displayAnswer": "", "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}], "sortAnswers": false}], "partsMode": "all", "maxMarks": 0, "objectives": [], "penalties": [], "objectiveVisibility": "always", "penaltyVisibility": "always"}]}], "allowPrinting": true, "navigation": {"allowregen": false, "reverse": true, "browse": true, "allowsteps": true, "showfrontpage": true, "showresultspage": "never", "navigatemode": "sequence", "onleave": {"action": "none", "message": ""}, "preventleave": true, "startpassword": ""}, "timing": {"allowPause": false, "timeout": {"action": "none", "message": ""}, "timedwarning": {"action": "none", "message": ""}}, "feedback": {"showactualmark": false, "showtotalmark": true, "showanswerstate": false, "allowrevealanswer": false, "advicethreshold": 0, "intro": "", "reviewshowscore": false, "reviewshowfeedback": false, "reviewshowexpectedanswer": false, "reviewshowadvice": false, "feedbackmessages": []}, "contributors": [{"name": "Jane Courtney", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/2154/"}], "extensions": [], "custom_part_types": [], "resources": [["question-resources/StarCircuit_zxgxKjR.png", "/srv/numbas/media/question-resources/StarCircuit_zxgxKjR.png"], ["question-resources/DeltaCircuit_NBsNnJk.png", "/srv/numbas/media/question-resources/DeltaCircuit_NBsNnJk.png"], ["question-resources/PSScircuit.png", "/srv/numbas/media/question-resources/PSScircuit.png"]]}