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Physics, Chemistry and Biology: Post your doubts here!

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Can anyone help me answer this question?
http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_w10_qp_61.pdf
question number 3 C
i cant seem to get the right answer which is 10 according to the ms!!

Theory suggest that when the current is 0.5I0, meaning 0.5 x I0 which is equal to 0.15 I believe.
This current is already given in the table, it's the last value .. and you had to fill in the resistance for the previous part by simply adding 3.3+6.8= 10.1

Now that you know that 10.1 ohms is when the TOTAL resistance in the circuit is 2x the resistance in resistor X

So let's take the resistance of resistor X as "R", and we get an equation as R+10.1= 2R

Hope this helped x)

I know I explained it bad, if you didn't get it.. I can try again.
 
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Ok draw the line with E1 below E and touching G and then above F....the angle between EGE1 should be 10degrees and FGF1 should also be 10 degrees....
Hope this helps with the further questions :D
thx, i thnk i'll get it:)
 
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Theory suggest that when the current is 0.5I0, meaning 0.5 x I0 which is equal to 0.15 I believe.
This current is already given in the table, it's the last value .. and you had to fill in the resistance for the previous part by simply adding 3.3+6.8= 10.1

Now that you know that 10.1 ohms is when the TOTAL resistance in the circuit is 2x the resistance in resistor X

So let's take the resistance of resistor X as "R", and we get an equation as R+10.1= 2R

Hope this helped x)

I know I explained it bad, if you didn't get it.. I can try again.

What do u mean 0.5Io means 0.5 * Io? What is Io?
I dont get the question :( plz help....
 
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What do u mean 0.5Io means 0.5 * Io? What is Io?
I dont get the question :( plz help....

All right.. one more time.
Did you see the question? In part (a) they ask you to record the reading on the ameter, which is 0.3. This reading is "Io", and in the next part of the question it says 0.5Io, which is 0.5 x Io. We already know what Io is so just multiply.
0.5x0.3= 0.15

Now take a look at the table, under the current column, the last reading is 0.15A. But there is no resistance..
Part b)ii) of the question asks to write the combined resistance of resistors 3.3 and 6.8 in series. Just add,
3.3+6.8= 10.1

NOW, the theory says the current will be 0.15 A ONLY when the TOTAL resistance in the circuit is 2x that of resistor X.
We already know that the COMBINED resistance of the other 2 resistors was 10.1, and the total resistance should be 2 times resistor X's.
So we can now make an equation if we take the resistance of resistor X as "R" (Just a variable)

R + 10.1 = 2R
10.1 = R

Resistor X's resistance = 10.1 Ohms.

Hope you got it this time x)
 
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All right.. one more time.
Did you see the question? In part (a) they ask you to record the reading on the ameter, which is 0.3. This reading is "Io", and in the next part of the question it says 0.5Io, which is 0.5 x Io. We already know what Io is so just multiply.
0.5x0.3= 0.15

Now take a look at the table, under the current column, the last reading is 0.15A. But there is no resistance..
Part b)ii) of the question asks to write the combined resistance of resistors 3.3 and 6.8 in series. Just add,
3.3+6.8= 10.1

NOW, the theory says the current will be 0.15 A ONLY when the TOTAL resistance in the circuit is 2x that of resistor X.
We already know that the COMBINED resistance of the other 2 resistors was 10.1, and the total resistance should be 2 times resistor X's.
So we can now make an equation if we take the resistance of resistor X as "R" (Just a variable)

R + 10.1 = 2R
10.1 = R

Resistor X's resistance = 10.1 Ohms.

Hope you got it this time x)

Isnt 0.3 recorded as Io so if its 0.5 then 0.5 is Io and not 0.5* I0??
I think Im just being an idiot but Im sorta confused....
 
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Theory suggest that when the current is 0.5I0, meaning 0.5 x I0 which is equal to 0.15 I believe.
This current is already given in the table, it's the last value .. and you had to fill in the resistance for the previous part by simply adding 3.3+6.8= 10.1

Now that you know that 10.1 ohms is when the TOTAL resistance in the circuit is 2x the resistance in resistor X

So let's take the resistance of resistor X as "R", and we get an equation as R+10.1= 2R

Hope this helped x)

I know I explained it bad, if you didn't get it.. I can try again.


i understood the first part but the last part im kinda comfused..
like what would the final answer be..
so if the total resistance of the circuit is 10.1 and its is twice the resistance of resistor x; then the value of resistor x is 5 ?
because it has half the value of the total resistance of the circuit?..
 
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Isnt 0.3 recorded as Io so if its 0.5 then 0.5 is Io and not 0.5* I0??
I think Im just being an idiot but Im sorta confused....

0.3 is recorded as Io, but the question says 0.5Io.

You know in maths when you have two things next to each other you know there multiplying, like 5a..
If a=3
Then 5x3 = 15.

Same thing here, 0.5Io just means 0.5xI0 which is equal to 0.15
 
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Fiduciual aid means that u add a pointer to the spring at the bottom then place a ruler and measure the length!
 
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i understood the first part but the last part im kinda comfused..
like what would the final answer be..
so if the total resistance of the circuit is 10.1 and its is twice the resistance of resistor x; then the value of resistor x is 5 ?
because it has half the value of the total resistance of the circuit?..

That explanation was bad, read my other post.. it's a few posts after that one.
 
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