OCR Physics A Exam - G482 Electrons, Waves, Photons [09/06/16]

For the question with 2 batteries in a circuit each with own internal resistance , it said the positive terminals of one battery was facing the positive terminal of another , so for that question were u just aloud to add the voltages to find total voltage?

Reply 121

Yooooooooo

Original post by MARCOS908

I selected 1 amps as the resistor with the LED was 167 ohms connected to in parallel to 21 (7 LED and resistor in parallel in each arrangement to make the number and there was 3 numbers) so the total resistance will be (21x(1/167))^-1 = 7.95 omhs so the current is 5/7.95 =0.628 amps therefore 1 amps fuse... Anyone else?

exactly what i did

Reply 122

username1969391

14

Original post by MARCOS908

I selected 1 amps as the resistor with the LED was 167 ohms connected to in parallel to 21 (7 LED and resistor in parallel in each arrangement to make the number and there was 3 numbers) so the total resistance will be (21x(1/167))^-1 = 7.95 omhs so the current is 5/7.95 =0.628 amps therefore 1 amps fuse... Anyone else?

It was a fuse for each number though wasn't it? Maybe I read the question wrong, either I'm pretty sure I got it wrong

Reply 123

dwhyte4

Original post by vking225

Just a list of prediction I think will come up based on from last years paper:
Longitudinal Transverse Waves
EM spectrum
Diffraction
Loads on Quantum Physics except photoelectric effect
They basically asked a lot on electricity so i have no idea what to expect.

This was rather a accurate

Reply 124

dwhyte4

Original post by Abb97

I put 6 ;_; don't know where 10-7 came from

I put 6 as well I think it depends on the value picked

Reply 125

MARCOS908

6

Original post by NickLCFC

It was a fuse for each number though wasn't it? Maybe I read the question wrong, either I'm pretty sure I got it wrong

I'm pretty sure it was a fuse for the whole thing I'm afraid

Reply 126

FemaleBo55

17

I put 1A for the fuse rating :frown:

I'm guessing I won't get a mark :frown:

because I've never seen a 50mA fuse ://

Posted from TSR Mobile

Reply 127

shahryair

6

Original post by Revision King98

For the question with 2 batteries in a circuit each with own internal resistance , it said the positive terminals of one battery was facing the positive terminal of another , so for that question were u just aloud to add the voltages to find total voltage?

from what i understand, pretty sure you had to subract them. cos the pd was 4.5-2.6 or whatever, im sure the voltage was 2.1, and the current was 1.05A

Reply 128

MARCOS908

6

Original post by FemaleBo55

I put 1A for the fuse rating :frown:

I'm guessing I won't get a mark :frown:

because I've never seen a 50mA fuse ://

I got 1 amp fuse too :smile:

Reply 129

Revision King98

1

Original post by shahryair

from what i understand, pretty sure you had to subract them. cos the pd was 4.5-2.6 or whatever, im sure the voltage was 2.1, and the current was 1.05A

Ohh so would I lose only one mark do u think if I added , and get ecf for rest of question ?

Reply 130

shahryair

6

Original post by Revision King98

Ohh so would I lose only one mark do u think if I added , and get ecf for rest of question ?

yh, it should be follow through. as some of the questions in the paper were worth 12/13 marks, screw part i and your done for the rest if no ecf.

Reply 131

teachercol

9

Original post by JosephKershaw

Will you also be doing one for the Depth in Physics Exam?

Yup
Created new thread for it

Reply 132

mtaraban12

1

Original post by teachercol

Yup
Created new thread for it

I am sorry but are you still planning to do G482?

Reply 133

teachercol

9

I've just done the paper. I'll type up my mark scheme and post it this afternoon.

Reply 134

seanthubb

5

Original post by NickLCFC

I said it was for safety reasons because if the variable resistor had a resistance of 0 and there was no fixed resistor, the current would be way too high (infinite?) and it would overheat.

Was a bit of a guess to be honest.

That's what I put, hope we're right

Reply 135

Brokensteps

3

Original post by MARCOS908

I'm pretty sure it was a fuse for the whole thing I'm afraid

Im fairly certain it said 1 fuse per number. I remember starting and multiplying it by 3, then realised and changed my answer

Reply 136

seanthubb

5

Easier than last year's paper I think, as I actually revised this time around. Still disappointed that I can never seem to do as well in the actual exam as I do in past papers (got 21 marks into an A on the last one I did before the exam). Anyway, good luck and I hope everybody gets what they wanted out of this!