Higher Physics 2011

Hey can someone help me with question 25 a ii? 2010 paper:/ Thanks!!

(edited 12 years ago)

Reply 81

Chandler

5

Original post by ChoccyLovaa

Hey can someone help me with question 25 a ii? 2010 paper:/ Thanks!!

Calculate the voltages at points P&Q using the voltage divider equation (this is S Grade electronics) The difference between these two voltages is the voltage displayed on the voltmeter.

Reply 82

Original post by Chandler

Calculate the voltages at points P&Q using the voltage divider equation (this is S Grade electronics) The difference between these two voltages is the voltage displayed on the voltmeter.

Which numbers do you use? I keep gettin the wrong answer still

Reply 83

Carissima

Original post by ChoccyLovaa

Which numbers do you use? I keep gettin the wrong answer still

Using the Voltage Divider Equation you Get

V_p= (1600/2400)*12 = 8

V_q = (6000/10000)*12 = 7.2

V_p - V-q = 0.8 V

Wrong numbers, but right answer. :confused:

Reply 84

Chandler

5

Original post by Carissima

Using the Voltage Divider Equation you Get

V_p= (1600/2400)*12 = 8

V_q = (6000/10000)*12 = 7.2

V_p - V-q = 0.8 V

Wrong numbers, but right answer. :confused:

You are doing the Vp & Vq calculations the wrong way.

Voltages are against a reference point of 0V. For Vp, R2 = 800, not 1600. For Vq, R2=4000, not 6000.

Yes, you get the right final answer your way but you have not got Vp & Vq right, so you probably won't get full marks as you used the wrong values. This is Standard Grade Physics (Electronics unit). Go back and look at your voltage divider notes from last year if you can't remember how to do it properly.

Reply 85

Carissima

Original post by Chandler

You are doing the Vp & Vq calculations the wrong way.

Voltages are against a reference point of 0V. For Vp, R2 = 800, not 1600. For Vq, R2=4000, not 6000.

Yes, you get the right final answer your way but you have not got Vp & Vq right, so you probably won't get full marks as you used the wrong values. This is Standard Grade Physics (Electronics unit). Go back and look at your voltage divider notes from last year if you can't remember how to do it properly.

I haven't done SG physics, shall look at the notes anyway. Thanks.

Reply 86

RyJ

Original post by tragicmagic

Do you ever feel the calculations are much easier than the questions you have to write sentences for? I always seem to get the written questions wrong!

YES! OH GOD YES! Thank God I'm not the only one....

Reply 87

RyJ

Original post by ChoccyLovaa

Can anyone help me with a question on the 2010 paper? It's question 25 a ii. How do you calculate the voltage? :/ Thanks.

I don't know how much this will help you but here goes: I remember doing this question a while ago, I remember that the Voltage on one side was 4.8V, the other was 4V therefore the P.D is 0.8V. If you can work back from that, as I say, sorry I don't remember the first bit.

Reply 88

zavvi16

Someone help me plz with Q 13 AND 14 MULTICHOICE FROM 2002 AND FROM 2010 Q 13 plz im freaking out

Reply 89

Original post by zavvi16

Someone help me plz with Q 13 AND 14 MULTICHOICE FROM 2002 AND FROM 2010 Q 13 plz im freaking out

I answered 13 and 14 on the first page, but if you need a better explanation, just ask :smile:

for q13 2010, the op-amp is inverting, which rules out answers A and B. Remember that Vgain = Rf/R1 and that Vo=V x (-Vgain). Substitute the values given and the correct answer will be -1=0.5 x (2/1) which is E.

Reply 90

soup

Do we have to know about pulleys for the exam? I can remember my teacher said something about it but we weren't really taught it.

Reply 91

RyJ

Original post by soup

Do we have to know about pulleys for the exam? I can remember my teacher said something about it but we weren't really taught it.

Not sure, wouldn't have thought so because I rarely see the questions, in fact I don't think I remember what one looks like...

Reply 92

I don't think i've ever done a pulley question...I'm almost certain there hasn't been one in any of the past papers I've done. Now I'm slightly concerned lol :P

Reply 93

Original post by RyJ

Not sure, wouldn't have thought so because I rarely see the questions, in fact I don't think I remember what one looks like...

Thanks

Reply 94

Omg I am freaking out.. I keep getting the wrong answer for everything :/ Multiple choice is ok but the written bit I keep doing the wrong thing and forgetting things arghh what's happened to me :frown:

Reply 95

Akmeeda

Question 9 from 2007. Seems like it should be easy but I have no clue how to do it :frown:

Struggle with multiple choice but i'm with questions 21-30. :/

http://www.sqa.org.uk/pastpapers/papers/papers/2007/H_Physics_all_2007.pdf

(edited 12 years ago)

Reply 96

Original post by Akmeeda

Question 9 from 2007. Seems like it should be easy but I have no clue how to do it :frown:

Struggle with multiple choice but i'm with questions 21-30. :/

http://www.sqa.org.uk/pastpapers/papers/papers/2007/H_Physics_all_2007.pdf

Work out the total resistance between P and Q

1/Rt=1/R1 + 1/R2
= 1/20 + 1/20
= 1/10
Rt= 1/(1/10)
= 10 ohms

Then use the formula
V=(R/Rtotal) x Vsupply
= (10/(10+20+20)) x 60
= (10/50) x 60
=12V

So the answer is A. Hope this helps :smile:

Reply 97

Akmeeda

Original post by akalasa

Work out the total resistance between P and Q

1/Rt=1/R1 + 1/R2
= 1/20 + 1/20
= 1/10
Rt= 1/(1/10)
= 10 ohms

Then use the formula
V=(R/Rtotal) x Vsupply
= (10/(10+20+20)) x 60
= (10/50) x 60
=12V

So the answer is A. Hope this helps :smile:

Thanks, it does help. But i'm still struggling with the other multiple choice questions, is there any revision website that concentrates on these types of questions? My teacher says to use GLOW but it's not letting me log in at the moment :/

Reply 98