Qualification > Queries

edexcel physics alternative to practical

<< < (3/6) > >>

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 8)

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  :'( >:(

Navigation

[0] Message Index

[#] Next page

[*] Previous page