"Take a deep breath, (Music starts) get ready for one of the most hypnotic things you'll ever see in a science class. Have you heard that heat rises? Well, here you can see it's true for yourself. I've got some food coloring on the bottom of a plastic container, and there's a hot mug right underneath the red food coloring. As it's heated, the water rises.
But I want you to look closely and notice something else. The blue on the sides is being drawn in. You can see it better when I speed it up. Here's the thing I want you to remember: when water moves FROM one place, it doesn't leave a void behind, water from somewhere else has to move in to take its place.
That's why you can see the blue food coloring coming in from the sides. You can see it better from above. Watch that blue food coloring get drawn in. Do you see it? The hot water reaches the top and then it gets pushed to the edges by more hot water rising underneath it.
As it goes out to the edges it starts to get cool, and cool water sinks just as hot water rises, and if you watch really carefully you can see it sink, and get drawn back toward the middle. These are called convection currents, and you see them moving here in two big ovals. They're one of the major things that drive ocean currents. Especially in the deep oceans, but it's not hot water rising that drives the ocean currents, it's really cold water sinking up near the poles.
Here's a piece of ice that I froze with some blue food coloring in it so you can see how cold water sinks. As water sinks at the North Pole, for example water has to flow up from the southern regions to take it's place, and these currents travel around the globe, some of them taking a thousand years to complete their course. Understanding convection currents will help you get a grip on weather systems, and the movements of earth's continents over the eons, and even the workings of a lava lamp. If you want to try this for yourself, click on this link for the directions you'll need Thanks for watching.
(Music fades out).Putri LaksmiDecember 11, 2017AdminBandung Indonesia
"Take a deep breath, (Music starts) get ready for one of the most hypnotic things you'll ever see in a science class. Have you heard that heat rises? Well, here you can see it's true for yourself. I've got some food coloring on the bottom of a plastic container, and there's a hot mug right underneath the red food coloring. As it's heated, the water rises.
But I want you to look closely and notice something else. The blue on the sides is being drawn in. You can see it better when I speed it up. Here's the thing I want you to remember: when water moves FROM one place, it doesn't leave a void behind, water from somewhere else has to move in to take its place.
That's why you can see the blue food coloring coming in from the sides. You can see it better from above. Watch that blue food coloring get drawn in. Do you see it? The hot water reaches the top and then it gets pushed to the edges by more hot water rising underneath it.
As it goes out to the edges it starts to get cool, and cool water sinks just as hot water rises, and if you watch really carefully you can see it sink, and get drawn back toward the middle. These are called convection currents, and you see them moving here in two big ovals. They're one of the major things that drive ocean currents. Especially in the deep oceans, but it's not hot water rising that drives the ocean currents, it's really cold water sinking up near the poles.
Here's a piece of ice that I froze with some blue food coloring in it so you can see how cold water sinks. As water sinks at the North Pole, for example water has to flow up from the southern regions to take it's place, and these currents travel around the globe, some of them taking a thousand years to complete their course. Understanding convection currents will help you get a grip on weather systems, and the movements of earth's continents over the eons, and even the workings of a lava lamp. If you want to try this for yourself, click on this link for the directions you'll need Thanks for watching.
(Music fades out).
Hey friends, welcome to the youtube channel
ALL ABOUT ELECTRONICS. Today we will see the concept of current,
voltage and power in the electrical circuits. And we will see that how they are related
to each other. So, let's start with the current.
So what is current? So, in simple terms, it can be defined as
a flow of electrical charge. So, to understand the current, first of let's
see the concept of electrical charge. So if you see any atom which is the fundamental
building block of any material, it consists of three primary elements. It contains proton and neutron which resides
in the nucleus and the electron moves around the nucleus in the orbits.
Now, the electron which is moving in the outermost
orbit can be easily knocked out of the atom by applying a little bit of energy. And these electrons which are in the outermost
orbit contributes in the flow of current. So, these electrons possess a negative charge,
while proton possesses a positive charge. Neutrons have a no charge or electrically
they are neutral.
So the same polarity charges have a tendency
to move away from each other. While the opposite polarity charges have a
tendency to move towards each other. The unit of the charge is Coulomb. And it is denoted by symbol Q or q.
When we talk about the charge of electrons
sometimes it is denoted by symbol e. So 1 electron has a charge of 1.6 X 10^ -19
Coulomb. So to have one coulomb of charge, we require
4.28 X 10^18 electrons, which is the inverse of this quantity. So to have one coulomb of charge, we require
the charge of these much electrons.
So as we have understood the concept of charge,
now let's talk about the concept of current. So, let's assume that we have a piece of copper
wire. And electrons are flowing through this copper
wire. And we want to find out that how many electrons
are flowing through this copper wire.
So, let's take one reference point in this
copper wire A-A'. That is the cross section of this copper wire. And let's assume that amount of charge that
is flowing through this copper wire is 1 C. So if 1 coulomb of charge is passing through
this reference point in one second, then we can say that the current which is flowing
through this copper wire is 1 C/S.
Or 1 Ampere. So the current can be defined as a rate at
which this electrical charge is passing through this reference point. The current is defined by a unit of an ampere. And it is denoted by the symbol I.
So to understand the concept of current, let's
take an example of tap water. The amount of water flowing through te tap
depends on the rate at which water particles are coming out of this tap. The higher the rate at which particles are
coming out of the tap. More will be the water flow.
Likewise, the higher the rate at which this
electrical charge or electrons passing through this reference point, the higher will be the
flow of current. So if 5 C of charge is passing through this
reference point in one second, then we can say that the flow of current is five ampere. So to have the movement of this charge, we
require some sort of energy. So, these electrons or electrical charge will
not contribute to the flow of current unless we apply some form of energy or external force.
At room temperature, these electrons move
randomly in all direction. Because of that net motion of flow is zero. So, to get the net motion of flow, we need
to apply some form of energy. So, let's apply this energy in the form of
an external battery, which connected to this copper wire.
So because of this battery, the electrons
will be supplied to the one end of the copper wire. So, electrons which are free electrons in
this copper wire will get repelled with this negative charge which supplied by this battery. And these free electrons will move to the
other end of the copper wire. And at the other end of the copper wire, they
will get attracted to the positive terminal of the battery.
So in this way, we get a flow of electrons
from the negative to the positive direction. So the electrons in the circuit flow from
the negative to the positive terminal. But in the electrical circuits, if you see,
we generally take a flow of current from positive to the negative direction. So that is the conventinal flow of current.
So, the conventional current flows from the
positive to the negative terminal of the circuit. So as we have discussed, to get movement of
this charge we require some sort of energy. And that energy is measured in the units of
a joule. So, let's assume that we have one coulomb
of charge and to move this charge from negative to the positive terminal, we require energy.
That is one joule. So if 1 Joule of energy is required to move
1 Cof charge from negative to the positive terminal then we can say that the potential
difference between the positive and the negative terminal is 1 volt. So, that is a definition of voltage. So, the voltage can be defined as an energy
required or work done to move a unit charge from one point to the another.
So, let's say we have two points A and B.
And at point A, we have 2 C of charge. So to move a 2 C of charge from one point
A to the B, let's say we require a 2 Jouls of energy. So, voltage or potential difference between
this point A and B can be defined as 2 J/2C, that is 1 Volt. The unit of this potential difference or voltage
is VOLT.
And it is denoted by symbol V. So the higher the amount of energy required
to move a charge from one point o the another point, the higher will be the potential difference. So, let's say if 5 C of charge is at point
A and to move this charge from point A to the point B, let's say we require 50 J of
energy. So the potential difference between the points
will be 50 J/5C = 10 Volt.
So to understand this concept, let's take
one example. Let's say we have one ball on the ground. And it's weight is 100 grams. Now, we want to through this ball from the
ground to the top of this building, which is having a height of 10 meters.
So for this task, we require some energy. Let's say for this task we require energy
E1. Now in another case, we have a ball with the
same weight or mass that is 100 gram. And we want to through this ball to the top
of one building which is having a height of 20 meters.
So for that let's say we require energy E2. Now, here energy E2 will be definitely greater
than the E1. Because the height in the second case is more. So the amount of energy required in the second
case will be the more.
So, we can compare this example with the voltage. The higher the difference between the two
points or higher the height of the building, higher the amount of energy is required to
throw a ball. Likewise, the higher the potential difference
between the twp points, more amount of energy is required to move a charge from one point
to the another point. So, now let's see the concept of power in
the electrical circuits.
So the power can be defined as the rate at
which energy is supplied or consumed in the system. So this power is denoted by symbol P.
And mathematically, it can be written as E/t. That is the rate at which energy supplied
or consumed in the system. So it is defined by unit Joule / Second.
Or Watt. While in the earlier case, Voltage mathematically
can be written as V= E/Q. That is the energy required to move a unit
charge. And the current I can be defined as rate at
which electrical charge is moving from the reference point,
that is Q/t.
Now as we were talking about the power, P=
E/t. So, let's understand the concept of power
by taking one simple example. Let's say we have one coulomb of charge at
point A. We want to move this charge from point A to
the point B.
And the energy required for this task is let's
say 5 Joules. And the time required for this task is let's
say 5 seconds. So by the definition of the power, P that
is defined by the rate at which energy is consumed. That is E/t.
Now here, in this case, to move 1 coulomb
of charge, we require 5 Jouls of energy. That is 5 Joules of energy per 1 Colomb. And the time required to move this 1 Coulomb
of charge is 5 seconds, That is 5 seconds / 1 Coulomb. So the power required for this task is 5J
/ 5 seconds, that is 1 watt.
Now, let's generalize this term. Let's say we require E joules of energy to
move Q amount of charge. And the time required for this task is t. That is t seconds for Q coulomb of charge.
That is power. So we can rewrite the term like, (E/Q) * (Q/t)
So E/Q is nothing but Voltage, as voltage can be defined as the energy required to move
a unit charge. And I, that is current can be defined as the
rate at which the charge is moving. So, we can write power as a product of V*I.
So, power can be defined as a product of V*I. So this very useful relationship between the
voltage, power and the current. Now in electrical circuits, The power is either
consumed or it is been supplied. So in electrical circuits, if you see any
element is either dissipating power or supplying a power.
So, how to know that element is supplying
a power or dissipating a power. This can find out by the simple sign convention,
So we will use this sign convention, to know
whether this element is supplying energy or it is dissipating energy. So let's say we have one element,
And the voltage between the two terminal is V. So if the current is flowing out of the positive
terminal of that element then we can say that that element is supplying a power.
Or if the current is flowing into the positive
terminal of that element then we can say that that element is dissipating a power. So, let's take one example to understand it
very clearly. Let's say we have two voltage sources,
which are connected through one resistor. We have one voltage source of 5V,
and another voltage source of 3 V.
They are connected by one resistor R.
So, the current will flow from higher potential to the lower potential, like water flows from
the higher elevation to the lower elevation. So, we will have a current in a clockwise
direction. And because of the flow of current, there
will be a potential drop across this resistorR. Let's say that is Vr.
Now, lets apply a sign convention across all
elements. So across the 5 volt source, the current is
flowing out of the terminal that means, this element or this source is supplying a power. Now, let's see a resistor,
So the current is entering into the positive terminal of the resistor. So the power is dissipated across this resistor.
Now, let's see across this 3 V voltage source. So across 3 V, current is entering into the
positive terminal. So this 3 V source is also dissipating an
energy or power. So 5V is supplying energy and the resistor
and 3V voltage source is dissipating the energy or power.
So by using this sign convention method, in
any network, we can find which elements are supplying the power and which elements are
dissipating the power. So let's summarize what we have seen in this
video. We have seen the current, voltage and power
in the electrical circuits and how they are related to each other. They are related to each other by this
P= V*I relationship.
So, hope you understood what is current, voltage
and power in the electrical circuits. If you have any query or doubts please let
me know in the coment section below. If you like this video, subcribe to the channel
ALL ABOUT ELECTRONICS..Putri LaksmiDecember 10, 2017AdminBandung Indonesia
Hey friends, welcome to the youtube channel
ALL ABOUT ELECTRONICS. Today we will see the concept of current,
voltage and power in the electrical circuits. And we will see that how they are related
to each other. So, let's start with the current.
So what is current? So, in simple terms, it can be defined as
a flow of electrical charge. So, to understand the current, first of let's
see the concept of electrical charge. So if you see any atom which is the fundamental
building block of any material, it consists of three primary elements. It contains proton and neutron which resides
in the nucleus and the electron moves around the nucleus in the orbits.
Now, the electron which is moving in the outermost
orbit can be easily knocked out of the atom by applying a little bit of energy. And these electrons which are in the outermost
orbit contributes in the flow of current. So, these electrons possess a negative charge,
while proton possesses a positive charge. Neutrons have a no charge or electrically
they are neutral.
So the same polarity charges have a tendency
to move away from each other. While the opposite polarity charges have a
tendency to move towards each other. The unit of the charge is Coulomb. And it is denoted by symbol Q or q.
When we talk about the charge of electrons
sometimes it is denoted by symbol e. So 1 electron has a charge of 1.6 X 10^ -19
Coulomb. So to have one coulomb of charge, we require
4.28 X 10^18 electrons, which is the inverse of this quantity. So to have one coulomb of charge, we require
the charge of these much electrons.
So as we have understood the concept of charge,
now let's talk about the concept of current. So, let's assume that we have a piece of copper
wire. And electrons are flowing through this copper
wire. And we want to find out that how many electrons
are flowing through this copper wire.
So, let's take one reference point in this
copper wire A-A'. That is the cross section of this copper wire. And let's assume that amount of charge that
is flowing through this copper wire is 1 C. So if 1 coulomb of charge is passing through
this reference point in one second, then we can say that the current which is flowing
through this copper wire is 1 C/S.
Or 1 Ampere. So the current can be defined as a rate at
which this electrical charge is passing through this reference point. The current is defined by a unit of an ampere. And it is denoted by the symbol I.
So to understand the concept of current, let's
take an example of tap water. The amount of water flowing through te tap
depends on the rate at which water particles are coming out of this tap. The higher the rate at which particles are
coming out of the tap. More will be the water flow.
Likewise, the higher the rate at which this
electrical charge or electrons passing through this reference point, the higher will be the
flow of current. So if 5 C of charge is passing through this
reference point in one second, then we can say that the flow of current is five ampere. So to have the movement of this charge, we
require some sort of energy. So, these electrons or electrical charge will
not contribute to the flow of current unless we apply some form of energy or external force.
At room temperature, these electrons move
randomly in all direction. Because of that net motion of flow is zero. So, to get the net motion of flow, we need
to apply some form of energy. So, let's apply this energy in the form of
an external battery, which connected to this copper wire.
So because of this battery, the electrons
will be supplied to the one end of the copper wire. So, electrons which are free electrons in
this copper wire will get repelled with this negative charge which supplied by this battery. And these free electrons will move to the
other end of the copper wire. And at the other end of the copper wire, they
will get attracted to the positive terminal of the battery.
So in this way, we get a flow of electrons
from the negative to the positive direction. So the electrons in the circuit flow from
the negative to the positive terminal. But in the electrical circuits, if you see,
we generally take a flow of current from positive to the negative direction. So that is the conventinal flow of current.
So, the conventional current flows from the
positive to the negative terminal of the circuit. So as we have discussed, to get movement of
this charge we require some sort of energy. And that energy is measured in the units of
a joule. So, let's assume that we have one coulomb
of charge and to move this charge from negative to the positive terminal, we require energy.
That is one joule. So if 1 Joule of energy is required to move
1 Cof charge from negative to the positive terminal then we can say that the potential
difference between the positive and the negative terminal is 1 volt. So, that is a definition of voltage. So, the voltage can be defined as an energy
required or work done to move a unit charge from one point to the another.
So, let's say we have two points A and B.
And at point A, we have 2 C of charge. So to move a 2 C of charge from one point
A to the B, let's say we require a 2 Jouls of energy. So, voltage or potential difference between
this point A and B can be defined as 2 J/2C, that is 1 Volt. The unit of this potential difference or voltage
is VOLT.
And it is denoted by symbol V. So the higher the amount of energy required
to move a charge from one point o the another point, the higher will be the potential difference. So, let's say if 5 C of charge is at point
A and to move this charge from point A to the point B, let's say we require 50 J of
energy. So the potential difference between the points
will be 50 J/5C = 10 Volt.
So to understand this concept, let's take
one example. Let's say we have one ball on the ground. And it's weight is 100 grams. Now, we want to through this ball from the
ground to the top of this building, which is having a height of 10 meters.
So for this task, we require some energy. Let's say for this task we require energy
E1. Now in another case, we have a ball with the
same weight or mass that is 100 gram. And we want to through this ball to the top
of one building which is having a height of 20 meters.
So for that let's say we require energy E2. Now, here energy E2 will be definitely greater
than the E1. Because the height in the second case is more. So the amount of energy required in the second
case will be the more.
So, we can compare this example with the voltage. The higher the difference between the two
points or higher the height of the building, higher the amount of energy is required to
throw a ball. Likewise, the higher the potential difference
between the twp points, more amount of energy is required to move a charge from one point
to the another point. So, now let's see the concept of power in
the electrical circuits.
So the power can be defined as the rate at
which energy is supplied or consumed in the system. So this power is denoted by symbol P.
And mathematically, it can be written as E/t. That is the rate at which energy supplied
or consumed in the system. So it is defined by unit Joule / Second.
Or Watt. While in the earlier case, Voltage mathematically
can be written as V= E/Q. That is the energy required to move a unit
charge. And the current I can be defined as rate at
which electrical charge is moving from the reference point,
that is Q/t.
Now as we were talking about the power, P=
E/t. So, let's understand the concept of power
by taking one simple example. Let's say we have one coulomb of charge at
point A. We want to move this charge from point A to
the point B.
And the energy required for this task is let's
say 5 Joules. And the time required for this task is let's
say 5 seconds. So by the definition of the power, P that
is defined by the rate at which energy is consumed. That is E/t.
Now here, in this case, to move 1 coulomb
of charge, we require 5 Jouls of energy. That is 5 Joules of energy per 1 Colomb. And the time required to move this 1 Coulomb
of charge is 5 seconds, That is 5 seconds / 1 Coulomb. So the power required for this task is 5J
/ 5 seconds, that is 1 watt.
Now, let's generalize this term. Let's say we require E joules of energy to
move Q amount of charge. And the time required for this task is t. That is t seconds for Q coulomb of charge.
That is power. So we can rewrite the term like, (E/Q) * (Q/t)
So E/Q is nothing but Voltage, as voltage can be defined as the energy required to move
a unit charge. And I, that is current can be defined as the
rate at which the charge is moving. So, we can write power as a product of V*I.
So, power can be defined as a product of V*I. So this very useful relationship between the
voltage, power and the current. Now in electrical circuits, The power is either
consumed or it is been supplied. So in electrical circuits, if you see any
element is either dissipating power or supplying a power.
So, how to know that element is supplying
a power or dissipating a power. This can find out by the simple sign convention,
So we will use this sign convention, to know
whether this element is supplying energy or it is dissipating energy. So let's say we have one element,
And the voltage between the two terminal is V. So if the current is flowing out of the positive
terminal of that element then we can say that that element is supplying a power.
Or if the current is flowing into the positive
terminal of that element then we can say that that element is dissipating a power. So, let's take one example to understand it
very clearly. Let's say we have two voltage sources,
which are connected through one resistor. We have one voltage source of 5V,
and another voltage source of 3 V.
They are connected by one resistor R.
So, the current will flow from higher potential to the lower potential, like water flows from
the higher elevation to the lower elevation. So, we will have a current in a clockwise
direction. And because of the flow of current, there
will be a potential drop across this resistorR. Let's say that is Vr.
Now, lets apply a sign convention across all
elements. So across the 5 volt source, the current is
flowing out of the terminal that means, this element or this source is supplying a power. Now, let's see a resistor,
So the current is entering into the positive terminal of the resistor. So the power is dissipated across this resistor.
Now, let's see across this 3 V voltage source. So across 3 V, current is entering into the
positive terminal. So this 3 V source is also dissipating an
energy or power. So 5V is supplying energy and the resistor
and 3V voltage source is dissipating the energy or power.
So by using this sign convention method, in
any network, we can find which elements are supplying the power and which elements are
dissipating the power. So let's summarize what we have seen in this
video. We have seen the current, voltage and power
in the electrical circuits and how they are related to each other. They are related to each other by this
P= V*I relationship.
So, hope you understood what is current, voltage
and power in the electrical circuits. If you have any query or doubts please let
me know in the coment section below. If you like this video, subcribe to the channel
ALL ABOUT ELECTRONICS..
In essence, electrical substations consist of power transformers, circuit breakers, ... ... And secondary systems for protection, load control and metering. The input signals for these secondary systems are provided by the CTs and VTs ...
... Which transform the primary currents and voltages into smaller signals. High primary currents are transformed into low currents of up to 1 or 5 amps, and high primary voltages into low voltages of up to 100 or 110 volts. The protection system uses these signals to continuously scan for faults, which enables it to quickly disconnect a faulted section from the grid.
The signals are also displayed in the control room, where they provide the data used for various switching actions. They are also needed for revenue metering. The polarity of these signals is of utmost importance, as a reversed polarity would give the secondary systems a false interpretation of the energy flow. In energy metering, a false interpretation of the energy flow based on reversed polarity ...
... Would cause the utility to pay for the energy that it delivers instead of receiving revenues. Polarity faults can lead to a protection system malfunction. There can be many reasons for improper polarity: The CT might have been installed with the wrong mechanical orientation.
A CT could have an internal wiring error. A single instrument transformers secondary wires may have been crossed ... Somewhere along the way to the secondary system. The secondary wires from two of the instrument transformers in a three phase system ...
... May have been swapped. The settings in the relay, meter, or control room device may have been set incorrectly. This is why the secondary systems correct wiring has to be verified ...
... Either during substation commissioning or after a refurbishment. Primary injection is used to validate the wiring. High currents of up to about a 1000 amps can be generated by larger testing equipment.
Smaller currents of about a 100 amps can be generated by smaller and more portable test sets. When a saw tooth signal with a distinct polarity has been used for injection, a handheld device can be used to validate the polarity throughout the system From the secondary side of the CT, along the secondary wiring all the way to the last terminal. Since this test is done phase by phase, all of the potential wiring errors or phase swaps can be detected. Testers should be able to move around the substation easily.
So ideally, they need light-weight, battery-operated equipment. The process of verifying voltage signal polarity is the same thing in principle, except that voltage is applied instead. If the wiring is correct, the secondary systems should run without a problem. COMPANO 100.Putri LaksmiDecember 10, 2017AdminBandung Indonesia
In essence, electrical substations consist of power transformers, circuit breakers, ... ... And secondary systems for protection, load control and metering. The input signals for these secondary systems are provided by the CTs and VTs ...
... Which transform the primary currents and voltages into smaller signals. High primary currents are transformed into low currents of up to 1 or 5 amps, and high primary voltages into low voltages of up to 100 or 110 volts. The protection system uses these signals to continuously scan for faults, which enables it to quickly disconnect a faulted section from the grid.
The signals are also displayed in the control room, where they provide the data used for various switching actions. They are also needed for revenue metering. The polarity of these signals is of utmost importance, as a reversed polarity would give the secondary systems a false interpretation of the energy flow. In energy metering, a false interpretation of the energy flow based on reversed polarity ...
... Would cause the utility to pay for the energy that it delivers instead of receiving revenues. Polarity faults can lead to a protection system malfunction. There can be many reasons for improper polarity: The CT might have been installed with the wrong mechanical orientation.
A CT could have an internal wiring error. A single instrument transformers secondary wires may have been crossed ... Somewhere along the way to the secondary system. The secondary wires from two of the instrument transformers in a three phase system ...
... May have been swapped. The settings in the relay, meter, or control room device may have been set incorrectly. This is why the secondary systems correct wiring has to be verified ...
... Either during substation commissioning or after a refurbishment. Primary injection is used to validate the wiring. High currents of up to about a 1000 amps can be generated by larger testing equipment.
Smaller currents of about a 100 amps can be generated by smaller and more portable test sets. When a saw tooth signal with a distinct polarity has been used for injection, a handheld device can be used to validate the polarity throughout the system From the secondary side of the CT, along the secondary wiring all the way to the last terminal. Since this test is done phase by phase, all of the potential wiring errors or phase swaps can be detected. Testers should be able to move around the substation easily.
So ideally, they need light-weight, battery-operated equipment. The process of verifying voltage signal polarity is the same thing in principle, except that voltage is applied instead. If the wiring is correct, the secondary systems should run without a problem. COMPANO 100.
Most of us don't think much
about the ocean's tides. Tide goes in, tide goes out. It's just some water moving because the moon and sun are pulling on it. But those words: "just some water" hide an
incredible amount of matter, and "pulling on it" hides an
unimaginable amount of force.
And nowhere is that more obvious
than right here. I'm just north of the Arctic Circle in Norway, half an hour's drive from a town called Bod. The land here is mostly what Douglas Adams
called 'lovely crinkly edges': and this particular lovely crinkly edge
holds the Saltstraumen Maelstrom: the most powerful tidal current on the planet. And the reason it's so powerful: that way is the sea.
That way is a fjord, a tidal inlet. Twice a day here, the sea rises and falls
by about two metres, so the water level in the fjord tries to equalise. The catch is that pretty much all the water
it needs to do that, 400 million cubic metres give or take, has to go through this channel. There are other routes that it could take, but the land masses make those slow and shallow.
They're winding country roads whereas this is like a twelve-lane freeway. It's... Well, it's a perfect storm. There's a huge mass of water on both sides
providing pressure, and the channel starts wide and
steadily narrows to the centre both ways.
It's the right width, and the right shape, to create this maelstrom of whirlpools and
currents and vortices. What surprised me the most, coming here and
standing next to it, is how much it changes, moment to moment,
second to second, every little twist in the tide and the water creates a new vortex and a new boil. I had to get close enough to
stick my camera in on a long pole, and honestly? It terrified me. Tour groups can take an inflatable boat
out into the channel, and you'll see occasional fishing vessels
taking advantage of all the marine life
that gets shunted through here.
But unlike the whirpools of myth and legend,
this maelstrom isn't going to pull a modern, bouyant,
powered boat down to the depths, although a swimmer on their own would be in
a lot of trouble, and a large ship might lose control and be
dashed against the rocks. But all this force, all this water, this is just a fraction of
what's being pulled around out on the ocean. It's just here it's visible,
it's on a human scale, it's threatening, so here we pay attention to it..Putri LaksmiDecember 10, 2017AdminBandung Indonesia
Most of us don't think much
about the ocean's tides. Tide goes in, tide goes out. It's just some water moving because the moon and sun are pulling on it. But those words: "just some water" hide an
incredible amount of matter, and "pulling on it" hides an
unimaginable amount of force.
And nowhere is that more obvious
than right here. I'm just north of the Arctic Circle in Norway, half an hour's drive from a town called Bod. The land here is mostly what Douglas Adams
called 'lovely crinkly edges': and this particular lovely crinkly edge
holds the Saltstraumen Maelstrom: the most powerful tidal current on the planet. And the reason it's so powerful: that way is the sea.
That way is a fjord, a tidal inlet. Twice a day here, the sea rises and falls
by about two metres, so the water level in the fjord tries to equalise. The catch is that pretty much all the water
it needs to do that, 400 million cubic metres give or take, has to go through this channel. There are other routes that it could take, but the land masses make those slow and shallow.
They're winding country roads whereas this is like a twelve-lane freeway. It's... Well, it's a perfect storm. There's a huge mass of water on both sides
providing pressure, and the channel starts wide and
steadily narrows to the centre both ways.
It's the right width, and the right shape, to create this maelstrom of whirlpools and
currents and vortices. What surprised me the most, coming here and
standing next to it, is how much it changes, moment to moment,
second to second, every little twist in the tide and the water creates a new vortex and a new boil. I had to get close enough to
stick my camera in on a long pole, and honestly? It terrified me. Tour groups can take an inflatable boat
out into the channel, and you'll see occasional fishing vessels
taking advantage of all the marine life
that gets shunted through here.
But unlike the whirpools of myth and legend,
this maelstrom isn't going to pull a modern, bouyant,
powered boat down to the depths, although a swimmer on their own would be in
a lot of trouble, and a large ship might lose control and be
dashed against the rocks. But all this force, all this water, this is just a fraction of
what's being pulled around out on the ocean. It's just here it's visible,
it's on a human scale, it's threatening, so here we pay attention to it..
In 2011, an international team of four astronomers
were looking through telescope data when they found evidence of
something unusual: A jet of matter was producing an electric
current of 3 exa amps a quintillion amps! Thats about as much current as youd
find in a trillion lightning bolts. It was the largest electrical current ever
discovered in space. And this jet is shooting out of the center
of a galaxy two billion light years from Earth. The galaxy is called 3C303, and its in
the direction of the Botes constellation, and its about a thousand times dimmer than
Pluto is on an average day.
So, its pretty hard to see this galaxy. But just because its not very bright in
visible light, doesnt mean it isnt bright in other
wavelengths of light. 3C303 was first observed back in 1981, by a series of radio telescopes in New Mexico
called the Very Large Array. The team of researchers who discovered the
huge electrical current used that data, plus follow-up observations
taken in 2010 and 2011.
They published their findings in The Astrophysical Journal Letters in October
2011. The main thing they found was this record-breaking
current, but they also discovered something else: the
jet itself is huge. Its being pushed outward at least 150,000 light years from the center of the
galaxy meaning that this jet is longer than the Milky
Way, which is 100,000 light years across. A jet this powerful must be fueled by something
even more powerful: the supermassive black hole in the center
of the galaxy.
Most big, active galaxies have supermassive
black holes. And lots of these supermassive black holes have huge jets of matter shooting away from
them. The jets come from a thin, rotating disk around
the black hole, called the accretion disk, which is made of
gas, dust, and even doomed stars that got too close to
the black hole. All this stuff is stuck rotating around the
black hole, pulled in by its gravity.
Itll either rotate forever or eventually
be sucked in and never seen again. The matter in this disk is spun at such high
speeds, and the turbulence heats it to such high temperatures, that the atoms break down into charged plasma
particles. And thats what leads to a huge electrical
current in the jet. The charged particles create electric and
magnetic fields, which eventually force some of this plasma
into a column, and shoots it outward in the form of a jet.
These speeding charged particles create electrical
current. Lots of electrical current. Of all the active galaxies with active supermassive
black holes in their centers, only about 10% have been found to have jets
spewing out matter. But all of these jets will have electric currents
running through them.
But why is 3C303s current so astonishingly,
exceptionally, record-breakingly huge? Well, the amount of current that these jets
carry is related to the strength of the black holes
accretion disk. Some of these jets shoot out for millions
of years, and others fizzle out. 3C303s black hole jet is thought to be
so electrified because its black hole accretion disk is so
active that it has an unusually strong magnetic field, which creates a larger amount of electricity. The researchers pointed out in their paper
that this was a rare opportunity and the first direct measure of the strength
of a large jets electric current.
But as radio telescopes become more sensitive, we should be able to observe more bright jets
like this one plus whatever giant currents are running through
them. Thanks for watching this episode of SciShow
Space, and thanks especially to our patrons on Patreon who help make this show possible. If you want to help us keep making episodes
like this, just go to patreon.Com/scishow to learn more. And dont forget to go to youtube.Com/scishowspace
and subscribe!.Putri LaksmiDecember 10, 2017AdminBandung Indonesia
In 2011, an international team of four astronomers
were looking through telescope data when they found evidence of
something unusual: A jet of matter was producing an electric
current of 3 exa amps a quintillion amps! Thats about as much current as youd
find in a trillion lightning bolts. It was the largest electrical current ever
discovered in space. And this jet is shooting out of the center
of a galaxy two billion light years from Earth. The galaxy is called 3C303, and its in
the direction of the Botes constellation, and its about a thousand times dimmer than
Pluto is on an average day.
So, its pretty hard to see this galaxy. But just because its not very bright in
visible light, doesnt mean it isnt bright in other
wavelengths of light. 3C303 was first observed back in 1981, by a series of radio telescopes in New Mexico
called the Very Large Array. The team of researchers who discovered the
huge electrical current used that data, plus follow-up observations
taken in 2010 and 2011.
They published their findings in The Astrophysical Journal Letters in October
2011. The main thing they found was this record-breaking
current, but they also discovered something else: the
jet itself is huge. Its being pushed outward at least 150,000 light years from the center of the
galaxy meaning that this jet is longer than the Milky
Way, which is 100,000 light years across. A jet this powerful must be fueled by something
even more powerful: the supermassive black hole in the center
of the galaxy.
Most big, active galaxies have supermassive
black holes. And lots of these supermassive black holes have huge jets of matter shooting away from
them. The jets come from a thin, rotating disk around
the black hole, called the accretion disk, which is made of
gas, dust, and even doomed stars that got too close to
the black hole. All this stuff is stuck rotating around the
black hole, pulled in by its gravity.
Itll either rotate forever or eventually
be sucked in and never seen again. The matter in this disk is spun at such high
speeds, and the turbulence heats it to such high temperatures, that the atoms break down into charged plasma
particles. And thats what leads to a huge electrical
current in the jet. The charged particles create electric and
magnetic fields, which eventually force some of this plasma
into a column, and shoots it outward in the form of a jet.
These speeding charged particles create electrical
current. Lots of electrical current. Of all the active galaxies with active supermassive
black holes in their centers, only about 10% have been found to have jets
spewing out matter. But all of these jets will have electric currents
running through them.
But why is 3C303s current so astonishingly,
exceptionally, record-breakingly huge? Well, the amount of current that these jets
carry is related to the strength of the black holes
accretion disk. Some of these jets shoot out for millions
of years, and others fizzle out. 3C303s black hole jet is thought to be
so electrified because its black hole accretion disk is so
active that it has an unusually strong magnetic field, which creates a larger amount of electricity. The researchers pointed out in their paper
that this was a rare opportunity and the first direct measure of the strength
of a large jets electric current.
But as radio telescopes become more sensitive, we should be able to observe more bright jets
like this one plus whatever giant currents are running through
them. Thanks for watching this episode of SciShow
Space, and thanks especially to our patrons on Patreon who help make this show possible. If you want to help us keep making episodes
like this, just go to patreon.Com/scishow to learn more. And dont forget to go to youtube.Com/scishowspace
and subscribe!.
"Take a deep breath, (Music starts) get ready for one of the most hypnotic things you'll ever see in a science class. Have you heard that heat rises? Well, here you can see it's true for yourself. I've got some food coloring on the bottom of a plastic container, and there's a hot mug right underneath the red food coloring. As it's heated, the water rises.
Hey friends, welcome to the youtube channel
In essence, electrical substations consist of power transformers, circuit breakers, ... ... And secondary systems for protection, load control and metering. The input signals for these secondary systems are provided by the CTs and VTs ...
Most of us don't think much
In 2011, an international team of four astronomers