Physics: Post your doubts here!

[mygjjk]

Anyone giving P33 on 7 May?

me

 

[hellodjfos;s'ff]

On what basis do you maintain significant figures when making a table in P3 ?

Raw readings are taken as it is for example, readings for time can be taken according to your stopwatch/timer reading - time readings are usually upto 1 or 2 decimal places(preferably 1 decimal place).
As for calculations in table, the answer/readings must be rounded to the same number of significant figures as your raw readings. For example, if length X=1.22cm, then 1/X could be calculated to 3 significant figures.

 

[hellodjfos;s'ff]

Never mind . Any useful tip regarding Electricity question in P3 because I always find setting up the circuit intriguing . TIA!

Setting up circuits for electricity is something I cannot help you with; problems in performing the experiment can only be fixed through practice. The only thing you can prepare for in P3 right before the exam is memorising the bullet-points for the last part of question 2. I would advise you to study/read the example candidate responses for P3 since they show you how a (near) perfect paper/response looks like.

 

[hellodjfos;s'ff]

How do you do bii) they multiplied the charge from bi by 2

This is fairly simple... So first of all, the current passing through the ammeter is 4.5 microammeter and using Q=It, we can determine that the charge flowing through the ammeter is 4.5 microcoloumb in 1 second. As the switch changes positions from X to Y 50 times in one second, the charge during one charging/discharging process is 4.5 microcoloumb divided by 50 which is equals to 9x10^-8... This will be the charge on one plate of the capacitor(and the other plate will have the same magnitude of charge with negative sign/opposite polarity).

 

[MShaheerUddin]

Please help with ( ii)
how can we sketch it? (please provide diagram)

 

[Ebrahim12]

Can someone mark the direction of the back emf generated by the relay here?

 

[Ebrahim12]

View attachment 64695
Please help with ( ii)
how can we sketch it? (please provide diagram)

You should link or screen shot the entire question.
Anyways:

The blue graph is the load voltage with the full bridge rectifier but without the capacitor
The red graph is with the capacitor added, minimum voltage of 3v

 

[Ebrahim12]

Anyone have a list of common circuits or something to answer these questions?

 

[hellodjfos;s'ff]

View attachment 64698

View attachment 64699
Anyone have a list of common circuits or something to answer these questions?

Whenever they ask for a use of an amplifier circuit, answer with 'variable voltmeter'. This answer works in most cases.

 

[zzgreat2105]

So .. tomorrow we all have variant 33 practicals.. here's what I've heard
For Q1.. They have some glass jars,clay and masses..
For Q2.. a clamp, the tennis ball type thingy and a wooden board and maybe even a protector too

 

[zzgreat2105]

So .. tomorrow we all have variant 33 practicals.. here's what I've heard
For Q1.. They have some glass jars,clay and masses..
For Q2.. a clamp, the tennis ball type thingy and a wooden board and maybe even a protector too

 

[zzgreat2105]

So .. tomorrow we all have variant 33 practicals.. here's what I've heard
For Q1.. They have some glass jars,clay and masses..
For Q2.. a clamp, the tennis ball type thingy and a wooden board and maybe even a protector too

 

[zzgreat2105]

So .. tomorrow we all have variant 33 practicals.. here's what I've heard
For Q1.. They have some glass jars,clay and masses..
For Q2.. a clamp, the tennis ball type thingy and a wooden board and maybe even a protector too

 

[mygjjk]

So .. tomorrow we all have variant 33 practicals.. here's what I've heard
For Q1.. They have some glass jars,clay and masses..
For Q2.. a clamp, the tennis ball type thingy and a wooden board and maybe even a protector too

hmm not sure for Q1, but maybe Q2 is about ramps then and rolling the ball?

 

[MShaheerUddin]

 

[hellodjfos;s'ff]

View attachment 64700

The question is related to part (a)... i cant see it. Send the whole question.

 

[MShaheerUddin]

 

[Rain0.0]

So .. tomorrow we all have variant 33 practicals.. here's what I've heard
For Q1.. They have some glass jars,clay and masses..
For Q2.. a clamp, the tennis ball type thingy and a wooden board and maybe even a protector too

too bad i only saw this after my p3 ended. btw how did you know?

 

[Rain0.0]

View attachment 64701

qp of?

 

[Rain0.0]

can someone suggest websites that provide full solutions?