Biology; Chemistry; Physics: Post your doubts here!

[farhan141]

Cmon tell me man, what is it and what it's used for????

 

[Zuhsid]

Cmon tell me man, what is it and what it's used for????

I have no idea at all..... thats the reason why i asked this question....!!

 

[bubbles1997]

Aoa. I finally managed to find Physics guess paper 2013. Please if you get benefit, like it!
#Physics predictions #O level
- Forces
- Pressure
- Electromagnetic waves
- Specific heat and Latent heat
- CRO
- Magnetism
- Practical Electricity (Live Wire, Fuses)
- Reflection and Refraction
- Relay switching
- Nuclear Physics (radioactivity)

 

[farhan141]

I

Aoa. I finally managed to find Physics guess paper 2013. Please if you get benefit, like it!
#Physics predictions #O level
- Forces
- Pressure
- Electromagnetic waves
- Specific heat and Latent heat
- CRO
- Magnetism
- Practical Electricity (Live Wire, Fuses)
- Reflection and Refraction
- Relay switching
- Nuclear Physics (radioactivity)

I'll fail if this comes OMG. What's relay switching, CRO

 

[Zuhsid]

I

I'll fail if this comes OMG. What's relay switching, CRO

Congrats..... u did not fail/die today!!!
Hopefully.....

 

[farhan141]

I still had a nightmare today. It was the worst paper ever I attempted.

 

[mAn_uNknoWn1997]

bring a magnet to each of the metals, the object which shows repulsion is a magnet while other is magnetic material

u cannot even have a metal..

 

[kiara15]

can anyone guide me how to calculate absolute errors in gradient and y intercept? alsoow to how to draw worst fit line in graph? plzz

 

[Zoya Shahab]

 

[AbbbbY]

View attachment 27812

Even though it's been a while since I studied Bio and am rather rusty, if I recall correctly, in an absence of light the plant will respire. This will mean it will give out CO2 instead of O2
Therefore, Tube 1 should be Acidic and Tube 2 should be Neutral.
Hence, Yellow and Orange.

Is this correct?
My apologies if it's not. Am pretty rusty on Bio.

 

[AbbbbY]

can anyone guide me how to calculate absolute errors in gradient and y intercept? alsoow to how to draw worst fit line in graph? plzz

Smallest division of the equipment / value obtained
Worse fit line? I'm sure you meant best fit.

Best fit refers to a line which touches at least two points on the line, and the rest evenly scattered. Say you had 8 plotted 8 points. 3 were on the line. 3 slightly above the line, 2 slightly below or vice versa is acceptable. 4 above 2 below etc are not.

Basically, you see by moving the ruler where the most points fall on the line-to-be and then see how many lie above and below. If out of 8 points 6 lie on the line then go ahead regardless of the other two. If no two points lie neatly/the value difference b/w the other lines is too much then you performed your practical way too inaccurately

 

[ZaqZainab]

View attachment 27812

omg i had the same question on my home exam
and in tube 1 it should be yellow and in 2 it should be orange
do let me know if i am correct or wrong

 

[ZaqZainab]

Even though it's been a while since I studied Bio and am rather rusty, if I recall correctly, in an absence of light the plant will respire. This will mean it will give out O2 instead of CO2
Therefore, Tube 1 should be Neutral and Tube 2 should be Acidic.
Hence, Orange and Yellow.

Is this correct?
My apologies if it's not. Am pretty rusty on Bio.

but respiring gives out CO2 instead of O2

 

[AbbbbY]

but respiring gives out CO2 instead of O2

Oh crap mixed them up being lost in other stuff simultaneously. My bad.

 

[ZaqZainab]

what do you think the answer should be and why

 

[ZaqZainab]

As the potential difference decreases the current increases right"?? right?
but how will you answer this s
should the graph not going downwards? like the gradient negative?

 

[Zoya Shahab]

Even though it's been a while since I studied Bio and am rather rusty, if I recall correctly, in an absence of light the plant will respire. This will mean it will give out CO2 instead of O2
Therefore, Tube 1 should be Acidic and Tube 2 should be Neutral.
Hence, Yellow and Orange.

Is this correct?
My apologies if it's not. Am pretty rusty on Bio.

the answer is correct but how do we know tht carbon dioxide is acidic???

 

[AbbbbY]

the answer is correct but how do we know tht carbon dioxide is acidic???

CO2 + H2O -> H2CO3 which is an acid.

 

[Salman Rahman]

As the potential difference decreases the current increases right"?? right?
but how will you answer this View attachment 27821s
should the graph not going downwards? like the gradient negative?

ans is A...

 

[Salman Rahman]

what do you think the answer should be and why View attachment 27820

the ans should be A or B...but how can the rays pass the lens without being refracted!??
which year??