At 4:40, what does it mean for the lines to pass another side of the area, why is this important? In the first situation, 12 field lines pass through the area, and after 12 field lines pass through the area. In the second situation,3 field lines pass through the area, and after 3 field lines pass through the area. I do not get the difference.
Good question. Notice how I emphasized that the lines pass from below the coil, and then from above the coil in situation B That is, there is a large change in the flux since it passes through in the opposite direction. It is like if you run to the right at 3 m/s and then you run to the left at 3 m/s, there is a large change in velocity even though there is not change in speed.
The d.c. current is constant. The idea of rms values is so that we can use the form of our d.c. equations for a.c. circuitry, in particular for the power equations.
Hi for 18:57 was wondering that V given is 110 V but thats not RMS. Why haven't u divided this by root 2 before using this value. Same for power.... why hasnt it been 1/2ed for average?
In a.c. we give rms values. In doing so we can use the same equations as we do for d.c. i.e. P=VxI etc. 110V is rms by default, we would need to specify that an a.c. voltage was a peak value if we that is what we wanted to communicate.
18:00 wouldn't the voltage across every bulb be different, how can we use the same voltage for every bulb? It's connected in series so wouldn't there be a voltage drop?
Easy to understand the concepts. I love your videos. However, if you could sort your videos into playlists of each topic it would be much easier to navigate around.
for the last question if the voltage were different and you used the equation P= (V^2)/R and solved for R you would not get the same resistance, does this mean that the resistance of the light bulb changes as voltage changes?
If we change the voltage, the power would change. The resistance would change as well for a lightbulb. Effectively, devices do not function properly without the rated voltage, and that means that they do not consume the same amount of power.
It would be equal to 1/2( Ipeak Vpeak), which is equal to (Irms Vrms). Like Chris said, the rms values are really just the dc equivalent for ac generators, which means we can use them in the dc equations.
I don't know what I would do without your help man! Thank you!
Great to hear. Thank you.
At 4:40, what does it mean for the lines to pass another side of the area, why is this important? In the first situation, 12 field lines pass through the area, and after 12 field lines pass through the area. In the second situation,3 field lines pass through the area, and after 3 field lines pass through the area. I do not get the difference.
Good question. Notice how I emphasized that the lines pass from below the coil, and then from above the coil in situation B That is, there is a large change in the flux since it passes through in the opposite direction. It is like if you run to the right at 3 m/s and then you run to the left at 3 m/s, there is a large change in velocity even though there is not change in speed.
i still do not get it unfortunately :(. i didn't understand the difference between above and below@@donerphysics
i now got it after really putting effort trying to understand it. now everything fits perfectly, thank you sir!
hi, for the question in14:53, why did you use the equation p=i^2 x r? why can't I use the equation Irms = Imax/root2 to find Imax for the dc current?
The d.c. current is constant. The idea of rms values is so that we can use the form of our d.c. equations for a.c. circuitry, in particular for the power equations.
Hi for 18:57 was wondering that V given is 110 V but thats not RMS. Why haven't u divided this by root 2 before using this value. Same for power.... why hasnt it been 1/2ed for average?
In a.c. we give rms values. In doing so we can use the same equations as we do for d.c. i.e. P=VxI etc. 110V is rms by default, we would need to specify that an a.c. voltage was a peak value if we that is what we wanted to communicate.
@@donerphysics then would R calculated also be in RMS? sine we have calculated the value of R with RMS values and if RMS is a default in a.c.
@@syl0378 Ris the same a.c. or d.c. R is the ratio of voltage to current whether that be peak or rms values.
18:00 wouldn't the voltage across every bulb be different, how can we use the same voltage for every bulb? It's connected in series so wouldn't there be a voltage drop?
The bulbs are in parallel. There would be different voltages across the 3 bulbs in series that would be proportional to the size of the resistor.
@@donerphysics Ahh okay got it, thanks a lot
Easy to understand the concepts. I love your videos. However, if you could sort your videos into playlists of each topic it would be much easier to navigate around.
Thanks Osama, The videos are in playlists. The link for the playlist that this video is included in is below,th-cam.com/video/0iQxlRessAs/w-d-xo.html
for the last question if the voltage were different and you used the equation P= (V^2)/R
and solved for R you would not get the same resistance, does this mean that the resistance of the light bulb changes as voltage changes?
If we change the voltage, the power would change. The resistance would change as well for a lightbulb. Effectively, devices do not function properly without the rated voltage, and that means that they do not consume the same amount of power.
Isn't the graph of P=VI (not considering the RMS), a |sinx| function?
V is a sine and I is a sine so VI will have a sine squared shape.
for the toaster question part (B), why isn't the equation (1/2) Irms V rms?
The idea of rms values is that the equations are the same in dc. or ac.
It would be equal to 1/2( Ipeak Vpeak), which is equal to (Irms Vrms). Like Chris said, the rms values are really just the dc equivalent for ac generators, which means we can use them in the dc equations.
Anselm Lohmann thank you!
For the last question, is it not a parallel circuit, so the current would split?
The current splits and that is why there are 3 calculations, one for each branch.
for the last q why dont u divide 110 by sqrt2 to find Vrms? is 110 the Vrms
Yes, a.c. values are always given in rms. If a peak voltage is given it must be specified that this is so.
at 16:17 you wrote 225/2.5 instead of 225/10, which gave 22.5
There was an annotation for this mistake but the annotations are no longer visible.
Thank you so much