How were your Physics P-1 and P-3?

[qpKillerqp]

No lets see
U have have output as 700,000 J
NOW THE EFFICIENCY IS 70 %
efficiency=output power/input power


70% is 70/100

70/100=700,000/input power

So input power =100/70 x700,000 =1,000,000 J

NOW IF U CONSIDER THEM !
700,000/1,000,000 = 70/100 =70 %

Simple

Yup yup,exactly what I did

 

[ChubbyBunny]

It came out for me 41.1 hours but all my friends are saying it's 24 or some sort

it came for me as 4 hours :/

 

[dubi2pro]

it was A

 

[qpKillerqp]

it was A

What do you mean?

 

[dubi2pro]

No varient 2 I did that
the current part was really tricky
I hope the gt is low

it was A

 

[dubi2pro]

reply to jannat123!

 

[Gamedos]

It came out for me 41.1 hours but all my friends are saying it's 24 or some sort

it is 24 because they said how many MORE hours will it take

 

[Gamedos]

Just wondering...how are you so sure of your answer?The clearly asked for PHYSICAL PROPERTIES and most of those you mentioned are chemical properties(I even googled most of them)

you could say conductivity of a metal

 

[qassem babel]

Guys lets all just hope we achieve the A*. Does anybody know if I lose around 30 marks from all of the 3 papers, would it still be an A* or an A?

 

[Gamedos]

Guys lets all just hope we achieve the A*. Does anybody know if I lose around 30 marks from all of the 3 papers, would it still be an A* or an A?

that depends on how did u do in paper 6 and 1
if u got for example 37 in paper 1 and 38 in paper 6 you MIGHT get an A* this also depends on the curve
but losing 3o marks in paper 3 u will probably get an A

 

[qassem babel]

no! I mean 30 marks total from all of the 3 papers, like 5, 5, paper 1 and 6, and like 20 from 3.

 

[Gamedos]

no! I mean 30 marks total from all of the 3 papers, like 5, 5, paper 1 and 6, and like 20 from 3.

so yeah u will get an A* inshallah

 

[Mr.Physics]

Hey buddies !!!
Lets consider that half life question !!!!
Q : A radioactive sample has an activity of 4800 counts /s. After 36 hrs, its count rate declines to 600 counts /s.
How many MORE hours will it take to reach to an activity of 159 counts /s ?

Ans: 0 halflife --------> 0 hrs -------> 4800 counts /s
X halflife -------> 36 hrs ---------> 600 counts



4800×1/8 = 600

1/8 means 3 half lives

If 3 half life take 36 hrs , 1 half lifd will take 12 hrs.

So
0 half life -----0hrs ------4800counts/s
1 half life------- 12hrs-----2400 counts/s
2 half life ------24 hrs ------1200 counts /s
3halflife -------36 hrs ------- 600 counts /s
4 half life ----- 48 hrs ------300 counts / s
5 half life ------- 60 hrs ------ 150 counts / s

Now for having an activity of 150 counts / s , we need 60 hrs.
But the question asked how many MORE hours will it take to reach to 150 counts / s
So the the answer was 60 - 36 = 24 hrs

HOPE HELPED !!!!!!

 

[Lola_sweet]

Hey buddies !!!
Lets consider that half life question !!!!
Q : A radioactive sample has an activity of 4800 counts /s. After 36 hrs, its count rate declines to 600 counts /s.
How many MORE hours will it take to reach to an activity of 159 counts /s ?

Ans: 0 halflife --------> 0 hrs -------> 4800 counts /s
X halflife -------> 36 hrs ---------> 600 counts



4800×1/8 = 600

1/8 means 3 half lives

If 3 half life take 36 hrs , 1 half lifd will take 12 hrs.

So
0 half life -----0hrs ------4800counts/s
1 half life------- 12hrs-----2400 counts/s
2 half life ------24 hrs ------1200 counts /s
3halflife -------36 hrs ------- 600 counts /s
4 half life ----- 48 hrs ------300 counts / s
5 half life ------- 60 hrs ------ 150 counts / s

Now for having an activity of 150 counts / s , we need 60 hrs.
But the question asked how many MORE hours will it take to reach to 150 counts / s
So the the answer was 60 - 36 = 24 hrs

HOPE HELPED !!!!!!

DUDE EXAM IS DONEEEEEEEEE!

 

[Mr.Physics]

DUDE EXAM IS DONEEEEEEEEE!

Yaar no problem !!!!
I was just explaining the solution -_-

 

[Mubariz Ahmed]

But I believe that pressure in liquids depend on depth (height) rather than the surface area of the base, and if both have the same initial volume and height, when you take equal volumes from both, they will end up with the same height once again. As a result, the pressure would remain the same? It is quite tricky to be honest :/

The answer is q because the height will not decrease as much as P......the top of the container q has more diameter

 

[Mubariz Ahmed]

The base has nothing to do with answer...But it's Q as the reason I stated


YES!!!One of the hardest questions...I did random stuff and apparantly my friends are saying I did it correct...I did "boiling point OF liquid and Freezing point OF liquid"

This is what i wrote, hope i,m right....
pressure in a gas and the electrical conductivity of a metal

 

[Yashnolkha]

It was around 22.1! what was yours?

Aayush Raj mine was also nearly 21

 

[Aayush Raj]

Aayush Raj mine was also nearly 21

I am really sorry to say but both our answers are wrong!!! Its around 47! because when ray moves from denser to rearer medium, (sin r/sin i) is the formula!

 

[Mr.Physics]

8

I am really sorry to say but both our answers are wrong!!! Its around 47! because when ray moves from denser to rearer medium, (sin r/sin i) is the formula!

u guys should use common sense
If the ray is moving from denser to less denser
So the angle of reflection would be higher than angle of incidence.