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

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He isn't

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[@Humansince2004]

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

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[@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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[@lakshikabhatia5754]

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[@fl3wer_ii]

Current comes in two flavors😍💅🏻

[@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).

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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 👍🙏

[@Sadiq749]

Current come in 2 flavours 😁0:38

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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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[@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]

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[@LearnInnovateAI]

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

[@omm12459]

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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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Best video about intro in AC

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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!

[@alilbitofbakht2626]

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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

[@santoshkute4082]

very clear

[@srinivasan3615]

In ac, if it moves back and forth, then how electron will reach destination

[@jaishreeram6596]

GOOD QUESTION

[@wa51m]

Same question bro

[@srinivasan3615]

Wasim i found answer later bro That electron will not move from source to destination. Electricity is the movement of electrons i.e electrons dont need to move from one place to another. When the electrons just move front and back, the electricity is produced.

[@aravindhgunti]

@@srinivasan3615 answer this question Why fan not rotating or changing its direction in one cycle of wave ? Why it is rotating in single direction? Bulb glows and offs In that case fan rotation should alter

[@srinivasan3615]

Aravindh Gunti fan converts electrical energy into kinetic energy (Disclaimer: i m not a eee student 😂 I know just the basics)

[@Mr.Xisdead]

Why can't we send low dc current and use the transformer to step up the current

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It's science of course 💨

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[@karuppiahmani8125]

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, 🤔

[@aloksatish777]

can the magnitude of dc current change?

[@rohitnagwal4177]

Sir, please answer ,"why fuse is connected to live wire only"?

[@nikhildhania5021]

Rohit Nagwal Fuse is connected with the phase wire(live wire) as the electric current flows from the live wire to neutral wire, hence in a case when current increase the live wire will get heated first as current flows through it first and then goes to the neutral wire. So in cases of voltage fluctuations the flow electric current needs to be stopped hence the fuse is connected with the live wire.

[@nikhildhania5021]

@@anmolrajput9133 live wire doesn't carry all the current. As current is a flow and hence it flows from live wire to neutral wire

[@abhimanyukushwaha1251]

Because if fuse is connected to neutral then in case of short circuit the fuse wire will break but still current with flow till electric appliance as it is still connected to live wire so, we may get electric shok if it is not connected to earthing.

[@pinkflower88]

What will happen if the current is too high??

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Superb🤘

[@askbatguy]

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