<p>It might have been an electric field. I know thats how televisions work.</p>
<p>The question with a steel spring, would the spring have a KE of its own? Yes right?</p>
<p>Quote from Wikipedia</p>
<p>“However, unlike Einstein, Bohr stuck to the classical Maxwell theory of the electromagnetic field. Quantization of the electromagnetic field was explained by the discreteness of the atomic energy levels; Bohr did not believe in the existence of photons.”</p>
<p>the answer was therefore the choice about the photons</p>
<p>Quoting wikipedia gives you the right answer?</p>
<p>Remember that the Bohr model of the atom does NOT give each energy level equal distance in between them.
I was watching an online caltech physics lecture and I specifically remember this.</p>
<p>If I remember correctly, the question just asked what was consistent with Bohr’s model, not what Bohr himself necessarily said or believed. The idea of light as a photon is certainly consistent with his model, while evenly-spaced energy levels are not. I could be remembering the precise wording of the question wrong, though.</p>
<p>What is prevalent view regarding difficulty of May physics subject test?
Do you guys think CB will have more stringent curve for this exam than usual?</p>
<p>i felt the may test was harder, but idk what i got since i canceled my scores. but maybe that’s just b/c i studied more for the june test.</p>
<p>What did you guys put for the question with the spring scale and the weights hanging from both sides. it asked for force displayed by the scale</p>
<p>also the engine efficiency question was simpler than that. it’s energy used over energy put in. in this case, 100 J/600 J or 17%.</p>
<p>10N for sure.</p>
<p>was 17% an option? idr</p>
<p>I’m pretty sure the efficiency question asked for maximum efficiency.</p>
<p>I had never heard of a spring scale before. Does it just measure the force on one side? It’s kinda frustrating… I know all the concepts, but I miss questions because they ask about specific instruments that I’ve never heard of before because I self-studied x.x</p>
<p>lol for the bohr one, wiki bohr atom and look at the size between the energy levels.</p>
<p>i put 0 N
the concept was equilibrium with torques
the spring doesn’t hold any weight, the pulleys get all of the weight
it’s like tug o war, one side pulls 10 N, the other side pulls 10N, net force= 0N</p>
<p>On the electron microscope question:
The microsopes definitely have an electron gun in them, but since the question was asking how it FOCUSES the image, is the answer magnetic field?</p>
<p>I also got 0 N on the spring scale because mg=mg so net force=0</p>
<p>Also on the ? with the square wire…induced current comes from change in magnetic FLUX which comes from moving the wire. Induced current doesn’t come from change in magnetic field. Not sure if what I put for the direction is correct (counterclockwise) but pretty sure there was induced current</p>
<p>anyone who took the may test remember the curve?</p>
<p>EDIT: Also, on the ? with the light going through the two slits and there was a random line with a point on it…was the answer on no other point on line L?</p>
<p>Guys, the answer to the spring ques is 10N for SURE. If the obvious logic doesn’t strike, try this-
Imagine the spring hung from the roof with a 10N wt. Now the roof will apply a force of 10N on the spring-wt. system. The reading on the scale will be 10N. The ques. given is no different than this except that they are using a direct force of 10N instead of a rigid support. Moreover, if you remove the 10N on the right, you’ll read 0 on the scale, coz the spring balance itself will accelerate to the right 
Remember that spring doesn’t measure net force on the ‘system’. There will not be a reading until the action-rxn pair is completed, in which case it will measure the force on any one side i.e. the tension in this case. If the forces are unequal, the system will have a net force of F1-F2 and balance will read the smaller of the forces.
Current was anti-clock I think. Magnetic fielld for micro is also certain. And slit one was more than any other point on the line or some similar meaning phrase.</p>
<p>^oh nvm you win
danggg i forgot even how a newton scale worked. wow i though the spring pulled in both directions. </p>
<p>and the light question with the waves was that it produces a bright fringe, but not necessarily the BRIGHTEST fringe because it is not the central maximum.</p>
<p>For the question about the direction of the induced current, was the condition of the experiment such that there was change in magnetic influx?</p>
<p>The questions in the beginning relating to the Spring with the weight attached, moving between points X, Y, and Z. What exactly was happening in that picture?</p>
<p>@Fernando- Yes, the thing was moving.
@pigs- lol, its not a war! And the answer is brighter than nearby points? Is it?
Btw, do we have a separate curve for internationals? I’m from India.
I heard that the curve was normally over -10 for 800! That’s insane IMO. 800 should be used to recognize a thorough knowledge. Not such a low % on a frighteningly easy test :(</p>
<p>moving in the field does not necessarily mean there was a change in magnetic influx</p>