How was physics paper 33

[mujtabashahnawaz]

this will not be a problem as the springs used were same throughout the experiment......problems with the springs will only change the magnitude of the gradient, not the sign(+ve or -ve)

So what do u think could have been a problem?!

 

[Knight]

So what do u think could have been a problem?!

i have no idea.

 

[Hertz]

Wasn't the cup already cylindrical? Mine was. :/

mine was like conical...n i could not use a rule to find out the diameter as water was not till top, so the diameter of opening was more than water level diameter...so i just estimated it to be like 6.5cm

 

[Knight]

mine was like conical...n i could not use a rule to find out the diameter as water was not till top, so the diameter of opening was more than water level diameter...so i just estimated to be like 6.5cm

mine was cylindrical n i got 6.9cm diameter

 

[floral123]

There's nothing wrong with using grams.

the only diff upto now is kg or g i think.....

 

[Knight]

the only diff upto now is kg or g i think.....

it's more then that......it's the gradient issue...which i think is not affected by the units(Kg or g).

 

[angelicsuccubus]

Guys i asked my sir he said for those who got a negative gradient only 1 mark will be deducted. People who mostly got the negative gradient didn't measure the First height accuratelyy..this is the truth !!

And how is that possible.. if they didn't measure the first height accurately.. the most inaccurate it can get is by the first height being less than the rest of the heights ... then you'd get a series of negative values for your h.-h/m column..... nobody did that. < that is not what a negative gradient means -_-

 

[angelicsuccubus]

it's more then that......it's the gradient issue...which i think is not affected by the units(Kg or g).

you know what? I have my values .. Im going to make a table where the mass is kg and where the mass is grams.... this really might make the difference (scared now)

 

[angelicsuccubus]

my cup was cylindrical..........but this is not a valid point as the only thing concerned was the surface area of the cup in contact with the air, not the shape of the cup or bowl....

no its valid cause the cup's opening's surface area was not the same as the surface area of the water and they asked you to measure the diameter of the surface area of the water. Was your cup uniformly cylindrical? Cause it wasnt meant to be.

 

[angelicsuccubus]

mine was like conical...n i could not use a rule to find out the diameter as water was not till top, so the diameter of opening was more than water level diameter...so i just estimated it to be like 6.5cm

hahahaha you know what I did? I took of my jacket and wrapped the sleeve around the water level, took the circumference and then measured the diameter XD (I know I wasn't meant to do that but I couldn't help myself when I knew I could get a more accurate d like that than with a ruler)

 

[angelicsuccubus]

Okay so kg or g.. would still give you a negative gradient.

 

[robotic94]

same as you but instead of no idea i wrote use a vernier caliper to find diameter.

Haha i wrote the same improvement, urrm because i could think of nothing else

 

[Ahsan Ausaf Ali]

My gradient was also negative....and y intercept was positive o.6205....i set up the apparatus correctly and perhaps i think the practical required a lot of precision to get accurate results because my 1 reading was anamolous...other 4 showed a decreasing trend but it had a lot of scatter and didnt necessarily go in continuous trend.......i was so confused....i used metres and kilograms for the units.........whie for second question...first temperature change was lyke 4 and 9.......k1=0.59....k2=0.77....i took the mean and arranged the data like 0.68 +-0.09.....and expained that since both values with in 13% of mean there is proportionility..........i think the threshold will fall as like 60% people....no 75% people got negative gradient and 15% got positive with 10% people getting no gradient at all [ 0 gradient...straight line]. this is evidence that the practical overall was a failure as it didnt perform well at all.........GT might be 30...........or 31......

 

[Muffy94]

My gradient was also negative....and y intercept was positive o.6205....i set up the apparatus correctly and perhaps i think the practical required a lot of precision to get accurate results because my 1 reading was anamolous...other 4 showed a decreasing trend but it had a lot of scatter and didnt necessarily go in continuous trend.......i was so confused....i used metres and kilograms for the units.........whie for second question...first temperature change was lyke 4 and 9.......k1=0.59....k2=0.77....i took the mean and arranged the data like 0.68 +-0.09.....and expained that since both values with in 13% of mean there is proportionility..........i think the threshold will fall as like 60% people....no 75% people got negative gradient and 15% got positive with 10% people getting no gradient at all [ 0 gradient...straight line]. this is evidence that the practical overall was a failure as it didnt perform well at all.........GT might be 30...........or 31......

i also got negative gradient!!!.........some body told me that we also had to add the other 100g mass hanging with larger thread in our reading to get correct points!!
is that true??????????

 

[Ahsan Ausaf Ali]

hey how many marks will get cut for the folowing:

not half of y axis used for graph
no quality mark due to large scatter
3 points are according to trend..but 2 points are not with trend ( eg the second value supposed to be smaller then first value but it is actuay bigger........
how many marks max they can cut for this......i personally think 3.............my ques 2 was great........where as i hope i q1 there is ecf for P and Q as i derived them correctly even though my grad might be wrong

 

[Ahsan Ausaf Ali]

i added 100 gram mass to larger thread................me initial height was o.601 metres ....then i added 150 grams as they said to short thread which was on side of the two springs in series.my height fell to o.507m.....the diff.. o.o94m...........all was going well for second reading was like 0.475, then o.445 then o.418.....then o.401 i think.....after when i calculated...i noticed that trend was giving neg grad but 2 values werent where they were supposed to be...i repeated.........got like better acuracy by 0.001.....but values still anaolous..........

 

[mujtabashahnawaz]

This was how u were supposed to set the apparatus

 

[Hertz]

my cup was cylindrical..........but this is not a valid point as the only thing concerned was the surface area of the cup in contact with the air, not the shape of the cup or bowl....

yes but i had difficult time measuring diameter so i just wrote it as i could not write anything....btw if this limitation question was asked for question one, it would have been easier. btw its only 2 marks for that point

 

[Hertz]

hahahaha you know what I did? I took of my jacket and wrapped the sleeve around the water level, took the circumference and then measured the diameter XD (I know I wasn't meant to do that but I couldn't help myself when I knew I could get a more accurate d like that than with a ruler)

lol but what was ur cup's diameter? mine was 6.5cm

 

[angelicsuccubus]

lol but what was ur cup's diameter? mine was 6.5cm

7.15 or 7.13 .. I don't think we get the same apparatus though so..... or maybe that was for the bowl.. i can't remember