Alternating current, direct current & what is frequency? | Physics | Khan Academy

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He isn't

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Current comes in two flavours ☺️☺️☺️☺️☺️ Edit : unexpected number of likes

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In particle physics there is actually 'flavours for particles'

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[@pinkflower88]

Answers: 1. DC - Direct current AC - Alternating current 2. If the frequency is 50 Hz it means that there are 50 cycles in a current per second. Also, it means that the current changes it's direction 100 times a second (a cycle consists of the change of direction twice) 3. Sending a large amount of voltage through long distances is uneconomical thus a better way to reduce the cost us to send much lower voltage through the same distance and then increase the voltage through a transformation when it reaches its required location. Now, since the transformer only works if the current is alternating, the current reaching our homes is AC. Feel free to correct my mistakes if any

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Mahesh Shehnoy---- Superb teacher❤️

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[@dingalarm]

Excellent video. Clear explanation 🙂 I believe another reason why high voltage / low current A.C is used in power lines is for cost reasons, so that thinner electrical cables (i.e. less copper) can be used.

[@JatPhenshllem]

Yeah, cause less energy is lost. There isn't as large a need to reduce resistance

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I too wish I had..

[@Jo-mz2my]

Transformer can be either step-up or step down. Especially in India, Transformers that we find near our home is step down. It converts high voltage ( usually 11 KV or 1100 Volts ) to low (415 volts). From the transformer three phase lines and one neutral is supplied to electric lines posts. Form that , one phase line and neutral line gives us normal 230 volts .

[@faxedits8]

@Jo Hello In ac current goes backwards and then foreword When it goes backward or forward does it cover the whole circuit once Or from some distance it come forward again

[@Jo-mz2my]

@@faxedits8The charges may not cover the whole circuit when it goes forward or backward. When the charges flow from one point to another, they will continuously change their direction in a to and fro manner and reach the final destination .

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Excellent explanation. Understood really much of everything about it. Thank you.

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Current comes in two flavors😍💅🏻

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[@webmaster8925]

If AC current “flows” in both directions, why is there a need to distinguish a live from a neutral wire?

[@valengammungvi1210]

The potential difference of the neutral is always kept very low(almost equal to zero).

[@abhiromnath73]

Good question..

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Well I used to think it's a camera problem

[@SmallTalkNetwork]

Fascinating... I knew nothing about electricity and I thought transformer do the opposite of what you just shared. Now I know better

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Thank you so much sir!! I was curious about this question : Why AC and not DC..??... But now I got it cleared sir... Thank you 👍🙏

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[@Sadiq749]

I also try this with tubelight it's fun👌🏻

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Current come in 2 flavours 😁0:38

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[@ABC869]

Sir , one question that troubles a lot of people , if current alternates why do we distinguish the 2 cables (for a single phase ) as hot wire and neutral . if it alternates then shouldn't for the first half cycle the brown wire (L) to be the hot one and blue wire (N) to be the neutral and for the second half cycle the brown wire to be the neutral one and blue wire to be the hot one ?

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[@wa51m]

Sir in AC if current goes back and forth how will the destination be reached

[@omm12459]

Electrons go back and forth in the entire circuit...so the electrons also move inside the electrical components coz it's also a part of the circuit...i think so... I'm not sure...but i my teacher answered me that it's electrical energy which reaches the destination...

[@LearnInnovateAI]

@@omm12459 you're right

[@omm12459]

@@LearnInnovateAI i have written 2 things .... which one is right?🤔

[@LearnInnovateAI]

@@omm12459 both, it's the energy that's being transferred by making electrons swing back and forth

[@omm12459]

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Sir, I have a doubt.... if one electron is moving through the bulb for many times back and forth, then it should have lost its energy . But it hasn't. The bulb still glows brightly, 🤔

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It seems to have a relation with persistence of vision

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[@jagadiswarchakraborty295]

When current flows through a bulb in our house, no short circuit. But if in the place of bulb a conductor is used, short circuit follows causing devastation. I do not think only consumption of electricity of the bulb can explain the thing.

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[@komalgond582]

What will be frequency of an A. C if its direction changes after every 0.01 second?

[@asgarh4589]

As direction changes for 0.01 sec, and also one cycle is of 2 directions, that implies 1 cycles takes a time of 0.02 secs... Frequency = 1/Time Period, here time period is 0.02 secs.... therefore, frequency = 1/(0.02) = 50 Hz... Hope this helps

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[@alilbitofbakht2626]

Sir do the electrons complete one complete cycle throughout the circuit before changing their direction?

[@KhanAcademyIndiaEnglish]

Totally depends on the frequency of alternation, the strength of the current, & the length of the wires At high currents (high speed), low frequency (more time to alternate), and smaller circuits, electrons might complete multiple loops before changing direction. Whereas in low currents, high frequency, and larger circuits, they might be just oscillating back and forth!

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@@KhanAcademyIndiaEnglish Thank you so much Sir for answering and making my concept clear🌺

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[@pinkflower88]

What will happen if the current is too high??

[@keshav1729]

*Sir Nikola Tesla made AC current*

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Done subscribing

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Brilliant explanation, best video on this topic

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Subscribed

[@dr.allwyndsouza5246]

Sir, if AC is the current driving behind tube lights and other devices, then why do fans rotate in one direction only, fans also receive AC, then fans should rotate in one direction and then in another direction, for a fan to rotate AC has to be converted in DC via rectifier, so my question is rectifier not used in powering tubelights ?

[@askbatguy]

really great video , just a seizure warning would have been nice on the flickering tubelight

[@iamthestrongest007]

Why the electrons flowing in A.C current moves back and forth, is it just to imagine or is it actually how it works? Well electrons bounce off of 1 atom to another, so does that mean it bounces and then bounces back to the same atom again? I can't understand why the electron are moving back and fourth in the A.C current.