AQA Physics PHYA4 - Thursday 11th June 2015 [Exam Discussion Thread]

Whichever one had the largest area. I remember it being a square with side length 0.5. If that one was option B then yes, B is correct.

It isn't acceleration the guy you quoted got it wrong. You are right rate of change of momentum is force which has the unit Newtons

Nope B is wrong as some energy is used to oppose resistance in the circuit

Yeah I said the needle would initially go in one direction and then in the opposite direction because of Lenzs law

Posted from TSR Mobile

Was the area 0.25 then? Cause I definitely remember that as the largest

10000% was not. 😂

Anyone remember what they got for the work done to move the 60nC charge?

Don't you get 4mJ from the battery and then minus 2mj to get the energy used up which is 2. So B couldn't havw been incorrect.

Yeah I said the needle would initially go in one direction and then in the opposite direction because of Lenzs law

Posted from TSR Mobile

Yeah b was incorrect that's what i'm saying

No, it was opposite direction as well. The flux through Q moves to the left as it decreases. The initial flux was to the right -- opposite

Yeah i thought this, half goes to capacitor half goes to resistor?

So did you put weight as the answer?

Some used in resistance of wires so not 50:50

As it initially enters coil Q it is moving in some horizontal direction through Q. Then when it decreases, it moves in the opposite direction because some of it essentially "returns" to coil P to account for the smaller current through P. Thus at any rate the second flux is opposite to the first.