O lvl physics quests
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the answer provided is 76.8ohms
couldn't tally no matter how i do.. anyone has the solutions?
a student is given a lamp labelled 12v,60w.with a aid of a circuit diagram,descirbe an experiment to enable the student to plot the voltage/current (V/I) characteristics graph for the lamp.
sketch a graph of the result you would expect to be obtained.(Do not use a graph paper).Explain the shape of the graph.
describe an experiment to determine values of voltage across a metallic conductor and the corresponding values of current in the conductor.Draw a labelled diagram of the circuit and explain how you would take the readings.
sketch the V?I characteristics graph for the metallic conductor and explain the shape of your graph.
kindly help? i bought the shinglee version of TYS that has no answers provided for structured questions..perhaps some1 with SAP version could share the ideal model answer with me... or maybe the highly educated ones out there could help in this..thx. -
Though I am not a physics student, but this is my first attempt to do a physics question.
For question 1, first you must find the resistivity.
Then use the resistivity to do part (b)
Must wait for physics students to see if my working are correct anot. -
wow is that required for combined physics?Originally posted by Darkness_hacker99:Though I am not a physics student, but this is my first attempt to do a physics question.
For question 1, first you must find the resistivity.
Then use the resistivity to do part (b)
Must wait for physics students to see if my working are correct anot. -
Yes. It's in the syllabus.Originally posted by amusing_dick:wow is that required for combined physics? -
x2.Originally posted by Darkness_hacker99:Yes. It's in the syllabus. 
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hey how about the other "essay" questions?? kindly share the answers with me?
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For the essay question I think I can't help you.Originally posted by amusing_dick:hey how about the other "essay" questions?? kindly share the answers with me?
Let's wait for physics students to help you solve the rest of the problem. -
I'm a bit busy... so I try to explain as briefly as possibleOriginally posted by amusing_dick:a student is given a lamp labelled 12v,60w.with a aid of a circuit diagram,descirbe an experiment to enable the student to plot the voltage/current (V/I) characteristics graph for the lamp.
sketch a graph of the result you would expect to be obtained.(Do not use a graph paper).Explain the shape of the graph.
experiment...
say need voltmeter, ammeter, and either a variable voltage supplier or a fixed voltage supply with a potentiometer to vary the input voltage
Use a few voltages (>6), and record the corresponding current values
Plot graph
sketch graph
Think a bit. power increase -> resistance increase for lamp
R = V/I
so u know V increase more proportionately than I
Hence, if you plot V-I graph, graph will curve upwards
if you plotted I-V graph, graph will curve downwards -
experiment same as aboveOriginally posted by amusing_dick:describe an experiment to determine values of voltage across a metallic conductor and the corresponding values of current in the conductor.Draw a labelled diagram of the circuit and explain how you would take the readings.
sketch the V?I characteristics graph for the metallic conductor and explain the shape of your graph.
sketch same method as above
for more info, look at here:
http://www.patent-invent.com/electricity/inventions/resistance.html -
ok another question here.
A wire of length L and cross sectional area of A has a resistance of 18ohms
calculate the resistance for a wire of same resistance with a length of 2L and 2A.
answer provided is 12ohm... couldn't get it.
kindly show the steps arriving at 12ohms for me?
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think answer wrong.Originally posted by amusing_dick:ok another question here.
A wire of length L and cross sectional area of A has a resistance of 18ohms
calculate the resistance for a wire of same resistance with a length of 2L and 2A.
answer provided is 12ohm... couldn't get it.
kindly show the steps arriving at 12ohms for me?
resistance for a wire of same resistance sounds wrong too... -
Can you double check the answer provided?Originally posted by amusing_dick:ok another question here.
A wire of length L and cross sectional area of A has a resistance of 18ohms
calculate the resistance for a wire of same resistance with a length of 2L and 2A.
answer provided is 12ohm... couldn't get it.
kindly show the steps arriving at 12ohms for me? -
Originally posted by eagle:
ok lets say if its the same material but the focus point is on the increase of length to 2L and cross sectional area to 2A.
think answer wrong.
[b]resistance for a wire of same resistance sounds wrong too...[/b] -
I'm sure you know the answerOriginally posted by amusing_dick:ok lets say if its the same material but the focus point is on the increase of length to 2L and cross sectional area to 2A.
R = pL/A
increase length to 2L and area to 2A will of course have the same effect.... still 18 ohms... that was why I said the answer given may be wrong... -
ok my lesson learnt is boycott shinglee TYS ans support only SAP.Originally posted by eagle:I'm sure you know the answer
R = pL/A
increase length to 2L and area to 2A will of course have the same effect.... still 18 ohms... that was why I said the answer given may be wrong... -
SAP is what?Originally posted by amusing_dick:ok my lesson learnt is boycott shinglee TYS ans support only SAP.
I thought is support only Homework Forum
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its Singapore Asian Publishing which produce better tys booklets than other tys producers out there like shinglee and dyna..Originally posted by eagle:SAP is what? -
Originally posted by eagle:
I guess the word should be resistivity.
think answer wrong.
[b]resistance for a wire of same resistance sounds wrong too...[/b] -
Yar.Originally posted by tanjun:I guess the word should be resistivity.