Recent content by CAH

Yea i did the 0-2 boundary, must have accidentally wrote -1! But I still have the area beneath the X axis in my equation and I don't know how to take it away so it's only the area in the first quad left...?

Homework Statement Find the volumes of the solid formed when each of the areas in the following perform one revolution about the X axis... Question: The volume line in the first quadrant and bounded by the curve y=x^3 and the line y=3x+2. Homework Equations Volume of revolution about X-axis...

how is this true? I get that it's the rate of change of flux, and if you have a graph of flux linkage against time, the gradient with a constant gradient then emf is constant since it IS the gradient... But how? If the flux linkage is increasing, why doesn't the emf?

So do the electrons in the copper get attracted/repulsed by the magnet causing them to move? And when you say changing B field do you mean it goes from zero (in the copper) to experiancing the magnetic field of the steel? Yes I think so. Thank you

If you drop a permanent magnet like steel through a copper tube it induces an emf, this is because you have a change in magnetic field/flux? But how? Why? The copper isn't producing a current before the magnet is dropped into it... Does something happen with the electrons in the copper?

Ah I see so it's just sigma^2/n, is this the same for all cases as in, calculating the variance of a sample and estimating a population variance?.. In other words, kinda, will it ever (a level standard) be 1/n^2 x var(x) Probably a stupid question, just checking

See the photo of the question+ mark scheme! I don't understand a question on finding an expression for the variance of something... Attempt at solution: also I worked out c as (3/2) previously, which is correct Var(U) = (3/2)^2 x Var(Xbar) = 9/4n^2 x a^2/18 I'll attach a photo of this too if...

Multimeter sorry! Isn't the accuracy half the smallest division?

I set an ohm meter to record current in mA, smallest 0.01mA, I took three readings for several different resistances.. What would the uncertainty be? And the same for the voltmeter but reading in volts, smallest 0.01V

I don't understand this still, Py= VI V= emf - rI Py= (emf - Ir)I ...=0

Hi I've attached the question and mark scheme, I don't understand part 6(d)... Why have they used sin90? nλ=dsinθ If there is another order beam how can it be known the angel at which it exists from the zero order? Thanks

See photo! Why does the power dissipated increase and then decrease (see graph)? Is it something to do with emf? Also can internal resistance change as the variable resistor increases/decreases or is it always constant? - this isn't one of the questions they ask I'm just wondering

If your doing an experiment to test how the temperature affects a thermistor (increase temp measure v and I...) why do you need a variable resistor in your circuit? Or if you don't NEED one what beneficial use may it pose anyway? Is it something to do with the current? Thanks

It's hard to type this out as there is a diagram and notation I can't find on the key board so I've attached an image of the question and answer. I've explained my solution below however I've also attached an image if it's too confusing with the lack of symbols! Problem involves uniform...

If it's below the x-axis is it calculating the area above the curve, between the curve and the x-axis above it