AQA Physics Unit 1 PHYA1 20th May 2013

AQA-PHYA1-W-QP-JAN13.pdf400.2KB

Original post by henpen

Do you happen to have the January 2013 paper? My teachers aren't able to log on to the teacher section of the AQA website.

I don't see anything wrong with doing so as for the people doing AS next year the June 2013 paper will be the unknown one that they can't access.

Don't worry if you can't.

Yeah

Reply 542

how is the voltmeter measuring 'lost volts'? is it not measuring pd across the variable resistor?

Reply 543

Original post by BenChard

how is the voltmeter measuring 'lost volts'? is it not measuring pd across the variable resistor?

Lost volt is the voltage lost inside the battery.

Reply 544

Original post by BenChard

how is the voltmeter measuring 'lost volts'? is it not measuring pd across the variable resistor?

I don't understand what your getting at?

Reply 545

Original post by StalkeR47

Lost volt is the voltage lost inside the battery.

the text says about as current increase, volts lots increase and pd decreases. I just need this explained please

Reply 546

Original post by Clarky747

I don't understand what your getting at?

voltmeter is not measuring lost volt. it is measuring the voltage at the resistor. however, as the current increases, the lost volt inside the battery also increases so the pd across battery terminal decreases. and therefore, the voltmeter reads lower value of voltage at the resistance. Again, this is because more voltage is being used up in the battery (increase in lost volt). Did you get this?

Reply 547

Original post by BenChard

the text says about as current increase, volts lots increase and pd decreases. I just need this explained please

As current increases. Heat dissipated in the battery increases and so more voltage is lost in the internal resistance of the battery as increased temperature increases voltage needed. Therefore as more volts are lost in the battery. The voltage shown on the voltmeter will have decreased.

Reply 548

Original post by StalkeR47

voltmeter is not measuring lost volt. it is measuring the voltage at the resistor. however, as the current increases, the lost volt inside the battery also increases so the pd across battery terminal decreases. and therefore, the voltmeter reads lower value of voltage at the resistance. Again, this is because more voltage is being used up in the battery (increase in lost volt). Did you get this?

thanks that's cleared things up :biggrin:

Reply 549

Original post by Clarky747

As current increases. Heat dissipated in the battery increases and so more voltage is lost in the internal resistance of the battery as increased temperature increases voltage needed. Therefore as more volts are lost in the battery. The voltage shown on the voltmeter will have decreased.

Yes! that is what I said.

Reply 550

Original post by BenChard

thanks that's cleared things up :biggrin:

Your welcome! :wink:

Reply 551

Original post by StalkeR47

Yes! that is what I said.

Sorry, you must of posted it while I was typing.

Reply 552

Original post by Clarky747

As current increases. Heat dissipated in the battery increases and so more voltage is lost in the internal resistance of the battery as increased temperature increases voltage needed. Therefore as more volts are lost in the battery. The voltage shown on the voltmeter will have decreased.

this also helped, thanks :rolleyes:

Reply 553

Original post by Clarky747

Sorry, you must of posted it while I was typing.

Oh! It is ok. :smile:

Reply 554

posthumus

20

Original post by BenChard

the text says about as current increase, volts lots increase and pd decreases. I just need this explained please

The volts are lost to increased heating due to current.... it becomes much lesser than the EMF value (which can be considered as like the true pd).

This is why you can only find EMF when the current is zero... because there's no heating in the circuit therefore no resistance.... therefore no loss of volts :tongue:

so you get the EMF, this of course practically never happens... there's always some kind of resistance :smile:

So that's why you use the graph from experimental data to predict the EMF value

Reply 555

Jatt.B

2

Hi does anyone have a list of all the experiments that could come up for 6 marker for unit 1?

Reply 556

Guys, what are the hardest electricity questions you have ever come across in the past papers?

Reply 557

henpen

Original post by Clarky747

Yeah

Excellent, you are by far the most useful person I know wrt the January 2013 papers.

Reply 558