edexcel physics alternative to practical

[7ooD]

relly bad exam only 3 papers to practice and half of the exam wasn't in these papers  

[Igcseboy]

wat was the answer to the resistivity and the first MCQ

[T.Q]

no exam discussion is allowed
until 24 hrs pass the exam time


By the way , i did that exam
it wasn't hard

[Omenbreed898]

It wasn't so hard

[Igcseboy]

no exam discussion is allowed
until 24 hrs pass the exam time


By the way , i did that exam
it wasn't hard

ok sorry

By the way ya i agree it wasnt tht hard :S:S

[7ooD]

yes i kno it wasn't hard i was just angry because of the first question of water datz why

[T.Q]

u can discuss the paper

[Black Kitty]

Yeah, u're right, u're talkin about the international written alternative to practicals for as?? I did it as well, it wasnt that hard......However, I had a few doubts, u thnk u can clear them for me??

1. 1st MCQ...the current answer was 20 mA??
2. 3rd MCQ i think....the LDR one...what was the dependent variable?
3. What would be the 3 precautions 4 measuring reaction time?? I've written avoiding paralax error, and keeping the device vertical, but could u clarify this 4 me?
4. How would you draw the ray path through the glass block??
5. The sini/sinr does pass through the origin, right? But how would you explain why?
6. I got the refractive index as 1.59..Some others got it like me, while others got quite diff values like 1.39, 1.48, etc...U think tht's right??

I know its gonna be a pain to ans all this, but jus be concise....Thanks....

[7ooD]

1- i did it 10A but then i changed it to 20m dunno wat is the right answer
2- the dependent i did it distance because it changes
3-i did excatly like u lool i said look 90 degrees to avoid parrelex error and use a set square to make sure it is vertical and i said 1 more i dnt remember
4-i said put a ruler under the glass so that we can kno where is the light ray im sure im wrong
5-i said if i is 0 then r is 0 then sin0 is 0
6-i got 1.4

[T.Q]

Yeah, u're right, u're talkin about the international written alternative to practicals for as?? I did it as well, it wasnt that hard......However, I had a few doubts, u thnk u can clear them for me??

1. 1st MCQ...the current answer was 20 mA??
2. 3rd MCQ i think....the LDR one...what was the dependent variable?
3. What would be the 3 precautions 4 measuring reaction time?? I've written avoiding paralax error, and keeping the device vertical, but could u clarify this 4 me?
4. How would you draw the ray path through the glass block??
5. The sini/sinr does pass through the origin, right? But how would you explain why?
6. I got the refractive index as 1.59..Some others got it like me, while others got quite diff values like 1.39, 1.48, etc...U think tht's right??

I know its gonna be a pain to ans all this, but jus be concise....Thanks....

dont double post

check here https://studentforums.biz/index.php/topic,7639.0.html

[temptress]

i chose 20mA as well
independent variable is distance and dependent is resistance, i suppose
our precautions match to some extent...in addition to that, i also wrote about repeating the procedure to find a mean value for reaction time 
i wrote something like, tracing the rays and block on to the sheet of paper and then joining the points after removal of the  block from the sheet
i said the graph will pass through the origin  i justified it by saying its in y=mx format  sounds stupid now..!
i don't remember the value for refractive index

and umm does the question under reaction meter part says to find best mean? should we use consistent values only?

[Black Kitty]

As for the above rest, I agree with y'all...But I still think

1. The dependent variable for the LDR should be distance probably
2. Any correct sini/sinr graph must pass through the origin....Check this out.....http://www.thealy.com/LCPhysics/exp/exp06/snell_values.htm
3. As for my value of 1.59, that too should be just right as the previous mark scheme guidelines tell the examiner to allow for the ans between a max diference of 0.3........

[temptress]

Independent variable is the variable controlled by the experimenter and dependent variable is the one that changes as a result..

In the question the experimenter changes distance (independent variable), and as a result resistance of LDR changes (dependent variable)

[nzpd9]

1.for the first MC Q. i put 20m,,dno if its right,..
2. independent variable was the intensity of the light since thats what they are controlling. They control this by changing the distance from the metal surface..distance is not the independant variable, for dependent variable i put resistance of LDR
3. for precautions of measuring reaction time i wrote:
1. Repeat nd take average
2. keep distance between thumb and finger the same each time
3. hold the carboard thing for measuring reaction time same distance above the persons thumb and fingers each time.
4. Ensure there are no distractions around the person- or same distractions etc.

4. Sini/Sinr passes through the origin since at an angle of incidence of 0 degrees i.e ray hits block at the normal, no refraction of the ray occurs and the ray passes straight through in a straight line. therefore, Sini/Sinr would be 0.
5. my refractive index was the gradient of the graph which was approx. 1.44...
thats all from me

[mayisha]

it ws such a weird paper ..... totally unlike the last 2 AND da specimen .... I scored 39 in da jan 2010 paper n 37 in the may 09 paper .... but for this .... i dont think i can even score above a 32 !!! God I hate edexcel !! N man I wish i gave da exam in jan