Insight 09?

[Jordan23]

Just did Insight 09 n just need to clear up a few things: Help would be much appreciated

Electric power:
Q15 - Doesn't feild point in Q not P
Q16 - Aren't light bulbs not ohmic conductors?

Light and Matter:
Q2 - When finding wavelength that would exist in emission spectra and not absorbtion spectra, are photons which result from loss of momentum of two colliding emission photons valid?
Q5 - Asked to calculate deBrogile wavelength and got answer of 1.2x10^-11m (same as theres in working of solution) isnt that 0.0112nm not 121nm
Q7 - If one slit is used instead of two doesn't the max gap need to be the same size as two wavelength since, interference will only occur if two wavelets pass through gap, or is the distance between wavelets 0 and two point sources are produced anyway?

[sachinmachin]

ELECTRIC POWER:
q15. remember that the current is flowing from the positive terminal to the negative terminal. thus from the direction of the   
current at each end, we can determine which end is north or south. ive learnt that where the current is flowing in an anticlockwise direction, that end is north. therefore the end, where the current is flowing in a clockwise direction, is south. using this, we can say that end P is north and end Q is south. thus the magnetic field will point towards Q.

q16. light bulbs are non-ohmic devices, therefore we can eliminate options B and D.

hope this clears this section.

[Jordan23]

ELECTRIC POWER:
q15. remember that the current is flowing from the positive terminal to the negative terminal. thus from the direction of the   
current at each end, we can determine which end is north or south. ive learnt that where the current is flowing in an anticlockwise direction, that end is north. therefore the end, where the current is flowing in a clockwise direction, is south. using this, we can say that end P is north and end Q is south. thus the magnetic field will point towards Q.

q16. light bulbs are non-ohmic devices, therefore we can eliminate options B and D.

hope this clears this section.

Q 15 - doesn't the bigger line on the cell represent positive terminal therefore current is flowing clockwise at P not Q, therefore should point to Q not P.
Q 16 - That's what I thought but the answer is B, which is a straight line (ohmic)

[sachinmachin]

q15. yes current is flowing clockwise at P. therefore end P should be south and end Q north. magnetic field will go FROM "Q" TO "P". you can use the right hand grip rule to clarify this.

q16. ah yes. since its been connected to a cathode ray oscilloscope. this somehow varies the voltage linearly with time, although im not quite sure on the background theory. i would research cathode ray oscilloscope's to gain a more sound understanding, however the answer in this case should be either A or C.

[Jordan23]

Thanks, anyone who is able to help with the remaining questions, will be much appreciated

[ryansecond5]

On q16, i think the answer is B because the question says that very small currents are used. Under such conditions i think the relationship can be approximated to be ohmic.
This is just my logic though so no guarantees

[jules]

Just a few question about some of these concepts from this exam would be great thanks
Electric Power Q 10
When sketching the emf voltage, because a commutator ring is used, does that mean the graph should look like a modulus cos graph, not the normal cos graph that they have in the answers?
Light Q6
Could someone explain how to determine the distance between the first order bright intensity line from the centre of the central maxima?
Cheers guys