Ocr a2 8 June exploring physics paper 2 8th June 2018 unofficial markscheme

For the 6 marker on the LDR, What was the emf of the cell and the resistance of the fixed resistor? Also, what answer did you guys get for the max and min reisistance?

For the graph one the amplitude stays constant and the frequency doubles.
This is because B is halved, but Change in time also halves so the rate of change of linked flux is the same, so the same EMF is induced.
Rotation of the coil is doubled so frequency is doubled. All other values were constant (Area and number of coils).

How? Because I got huge number I knew was dodgy because it's meant to be small :/

:O How'd you found the image :O

and yeah reflects and diffracts around corners

surely its refraction lol

It doesn't pass through a different media so it doesn't refract, it simply reflects off the surface

That's probably true though I don't think it necessarily has to pass into a different medium to refract . Water waves slow down when entering areas which are shallower and I believe they refract because of this, but they're not technically passing into a different medium. There could have been a bit of refraction but I doubt they'll accept that as you have just said. I put reflection and interference so I hope they accept that...

150 and 1.5x10^3 ohms ... emf not a clue

what was the si unit for the resistance