PoojaMoolya: Created page with "{|border=1 |- || '''Time''' || '''Narration''' |- || 00:01 || Welcome to the Spoken Tutorial on '''Magnetism''' and '''Electromagnetism'''. |- || 00;07 || At the end of thi..."

2020-09-15T05:05:51Z

Created page with "{|border=1 |- || '''Time''' || '''Narration''' |- || 00:01 || Welcome to the Spoken Tutorial on '''Magnetism''' and '''Electromagnetism'''. |- || 00;07 || At the end of thi..."

New page

{|border=1
|-
|| '''Time'''
|| '''Narration'''

|-
|| 00:01
|| Welcome to the Spoken Tutorial on '''Magnetism''' and '''Electromagnetism'''.

|-
|| 00;07
|| At the end of this tutorial you will be able to,

|-
|| 00:11
|| Draw magnetic field lines for a bar magnet.

|-
|| 00:15
|| Verify right hand thumb rule.

|-
|| 00:18
|| Verify Fleming's left hand and right hand rules.

|-
|| 00:23
|| Simulate the working of a generator.

|-
||00:26
|| Here I am using,

Ubuntu Linux OS version 16.04

|-
|| 00:32
||Firefox web browser version 62.0.3

|-
|| 00:38
|| To follow this tutorial, learner should be familiar with '''Apps on Physics'''.

|-
|| 00:43
||For the pre-requisites tutorials please visit this site.

'''https://spoken-tutorial.org/'''
|-
|| 00:49
|| In this tutorial we will use, '''Magnetic Field of a Bar Magnet'''

|-
|| 00:56
||'''Magnetic Field of a Straight Current-Carrying Wire'''

|-
|| 01:00
||'''Lorentz Force''' and '''Generator Apps'''.

|-
|| 01:04
|| I have already downloaded '''Apps on Physics''' to my '''Downloads''' folder.

|-
|| 01:09
|| Right click on''' magneticfieldbar_en.htm '''file.

|-
|| 01:15
||Select '''Open With Firefox web Browser '''option.

|-
|| 01:19
||'''Magnetic field bar App''' opens.

|-
||01:22
|| The '''App''' opens showing a magnet and a magnetic needle.

|-
|| 01:28
|| On the green panel there are two buttons.

'''Clear field lines''' and '''Turn magnet'''.

|-
|| 01:35
|| Poles of a bar magnet and compass needle are represented by the following colors.

|-
|| 01:41
||Red for north pole and green for south pole.

|-
|| 01:46
|| Click on '''Turn magnet '''button.

|-
|| 01:49
||Observe that both bar magnet and magnetic needle change their direction.

|-
|| 01:55
|| Let us draw the magnetic field lines.

Place the cursor on the magnetic needle.

|-
|| 02:02
||Click on the magnetic needle and move the needle up and down to draw the magnetic lines.

|-
|| 02:09
||Continue to draw the lines as shown here.

|-
|| 02:13
|| Click on the '''Clear field lines '''button.

|-
|| 02:17
|| Click on '''Turn magnet''' button.

|-
|| 02:20
|| Again draw the magnetic lines around the magnet.

|-
|| 02:25
|| When we turn the magnet, the lines of force change the direction.

|-
||02:30
|| The direction of magnetic field outside the bar magnet is from north to south.

It is shown by the arrows.

|-
|| 02:39
|| Magnetic field is strongest inside the bar magnet.

|-
|| 02:44
||Outside the bar magnet it is strongest near the poles.

|-
|| 02:49
||What is the direction of magnetic field inside the bar magnet?

|-
|| 02:55
|| Next we will move on to '''Magnetic Field Line in a Current Carrying Wire App'''.

|-
|| 03:00
|| Right click on '''magneticfieldwire_en.htm''' file.

|-
|| 03:06
||Select '''Open with Firefox Web browser''' option.

|-
|| 03:10
|| The '''App '''opens showing magnetic field lines around a current carrying wire.

|-
||03:16
|| On the right side of the screen we have a '''Reverse current''' button.

|-
|| 03:22
|| The red arrow indicates the direction of the current.

Note that the direction of current is opposite to that of electrons.

|-
|| 03:33
|| The signs at the end of the wire symbolizes the terminals of the connected battery.
|-
|| 03:40
|| The concentric circles are the magnetic field around the current carrying wire.

|-
|| 03:46
|| Let us find the direction of magnetic field using right hand thumb rule.

|-
||03:53
||Observe the picture and put your right hand as follows.

|-
|| 03:58
|| Put your right hand thumb in the direction of the current.

|-
|| 04:03
|| Now curl your fingers inside.

|-
|| 04:07
||Fingers gives you the direction of magnetic field.

|-
|| 04:12
|| As an assignment,

Reverse the current flow and determine the magnetic field.

|-
|| 04:19
|| Let us move on to the next '''App''', '''Lorentz Force'''.

|-
|| 04:24
||Follow the same steps as we used for previous '''App '''to open '''htm''' file.

|-
|| 04:31
|| Interface shows a horseshoe magnet through which a conducting wire is passed.

|-
|| 04:37
|| The blue arrows shows the direction of the magnetic field.
|-
|| 04:42
|| On the green panel we have the following buttons.

'''On/Off ''', '''Reverse current ''' and '''Turn magnet'''.

|-
|| 04:51
|| When the circuit is open, the wire is shown in black colour.

|-
|| 04:56
|| Click on the '''On/Off''' button to complete the circuit.

|-
|| 05:01
|| Notice that the wire is in conduction mode.

|-
|| 05:06
||This is indicated by the red coloured wire.

|-
|| 05:10
|| At the bottom, there are three check-boxes.

These are '''Current direction''', '''Magnetic field''' and '''Lorentz force'''.

|-
|| 05:20
|| The black arrow pointing towards right is the '''Lorentz force'''.

|-
|| 05:26
|| '''Lorentz force''' is always perpendicular to the magnetic field.

|-
|| 05:31
|| To change the direction of magnetic field, click on the '''Turn magnet''' button.

|-
|| 05:38
|| Let us verify the direction of '''Lorentz force '''using '''Fleming’s left-hand rule.'''

|-
|| 05:45
|| Press''' F5''' key on the keyboard to restart the '''App'''.

|-
|| 05:50
|| First uncheck the '''Lorentz force''' check-box.

|-
|| 05:54
|| Click on '''On/Off''' button.

|-
|| 05:57
|| Now keep your fingers of the left hand as suggested here.

|-
||06:03
|| Index finger pointing in the direction of magnetic field. Middle finger pointing in the direction of current.

|-
|| 06:13
||Thumb shows the direction of Lorentz force.

|-
|| 06:17
|| Here the direction of Force is towards the right-side.

This is Fleming’s left-hand rule.

|-
|| 06:25
|| Let us verify our answer by checking the '''Lorentz force '''check-box.

|-
|| 06:31
||Observe that the direction is same as shown in the '''App'''.

|-
||06:36
|| As an assignment

Reverse the current flow.

|-
|| 06:40
||Determine the direction of lorentz force using Fleming’s left hand rule.

|-
|| 06:47
|| Now let us open the '''Generator App'''.

|-
|| 06:51
|| I will open the '''App '''as before.

|-
|| 06:55
|| The '''App '''shows a generator.

|-
|| 06:58
|| An electrical generator converts mechanical energy into electrical energy.

|-
|| 07:05
|| The '''App '''opens showing a horseshoe magnet.

|-
|| 07:09
||A rectangular current carrying coil is inserted between the poles of the magnet.

|-
|| 07:15
|| On the green panel, we can change the rotations per minute using the slider.

|-
|| 07:22
||By default the rectangular coil rotates 6 rotations per minute.

|-
|| 07:28
||We can change the rotation of the coil to a maximum of 12 rotations per minute.

|-
|| 07:35
|| Increase the rotation to 12 rotations per minute.

|-
|| 07:40
||In the graph we can see two complete cycles in one minute.

|-
|| 07:46
||Here the frequency of the maximum output voltage is doubled.

|-
|| 07:52
|| The rectangular coil is connected to the voltage source through the slip rings.

|-
|| 07:58
|| Observe that the rectangular coil is rotating about an axis.

This coil is perpendicular to the magnetic field.

|-
|| 08:09
|| Here rotation of the rectangular coil is a source of mechanical energy.

|-
|| 08:16
|| Due to the rotation of the coil, current is induced into the wire.

|-
|| 08:22
||The red arrow represents the direction of the induced current.

|-
|| 08:27
|| In the green panel we can choose an '''AC''' generator or '''DC '''generator.

|-
|| 08:34
|| By default '''Without commutator''' an '''AC '''generator is selected.

|-
|| 08:40
||Select '''With commutator '''radio button.

|-
|| 08:44
||Commutator is a device for reversing the direction of flow of current.

|-
|| 08:50
||This device ensures that the current flows only in direct current mode.

|-
|| 08:57
||Hence '''With Commutator''' means, the generator is a '''DC''' generator.

|-
|| 09:03
|| On the top of the circuit, voltage v/s time graph is plotted.

|-
|| 09:09
||This is the graph of a '''DC''' generator.

|-
|| 09:13
|| In the graph, moving blue point indicates the change in voltage.

|-
|| 09:19
|| '''Change direction''' button changes the direction of the rectangular coil.

|-
|| 09:25
||Click on the '''Change direction '''button.

|-
|| 09:28
||Observe the change in the direction of rectangular coil.

Also notice the change in the graph.

|-
|| 09:37
|| Press '''F5''' key on the keyboard to restart the '''App'''.

|-
|| 09:42
|| We can find the direction of induced current using Fleming’s right-hand rule.

|-
|| 09:49
|| This rule is same as Fleming’s left-hand rule.

|-
|| 09:53
|| Click on the '''Pause''' button.

|-
|| 09:56
|| Now arrange fingers of your right hand as shown in the figure.

|-
||10:01
||We can determine the direction of magnetic field using Fleming's right hand rule.

|-
|| 10:07
|| There are three check-boxes at the bottom of the green panel.

|-
|| 10:12
||'''Direction of movement,''' '''Magnetic field '''and '''Induced current'''.

|-
|| 10:18
|| Uncheck the''' Magnetic field''' check-box.

Notice that the magnetic field lines disappear.

|-
|| 10:27
|| In the similar way we can uncheck the remaining check-boxes if not required.

|-
|| 10:33
|| Press '''F5''' key on the keyboard to restart the '''App'''.

|-
||10:38
|| '''AC''' generator is an alternating current generator.

|-
|| 10:43
||So, here the graph shows positive as well as negative voltages.

|-
|| 10:49
|| As an assignment,

Change the rotations per minute to 0, 3.0, 6.0 and 9.0

|-
|| 10:57
||Note the changes in the movement of the coil and graph.

Explain the reason for the changes.

|-
|| 11:06
|| Let us summarise

|-
|| 11:08
|| Using these '''Apps '''we have,

Drawn magnetic field lines of a bar magnet.

|-
|| 11:15
||Verified right hand thumb rule.

|-
|| 11:18
||Verified Fleming's left hand and right hand rules.

|-
|| 11:23
||Simulated the working of a generator.

|-
|| 11:28
|| These Apps were created by Walter Fendt and his team.

|-
|| 11:33
|| The video at the following link summarises the Spoken Tutorial project.

Please download and watch it.

|-
|| 11:41
|| The '''Spoken Tutorial Project'''team, conducts workshops and gives certificates.

For more details, please write to us.
|-
||11:51
|| Please post your timed queries in this forum.

|-
||11:55
|| The Spoken Tutorial Project is funded by MHRD, Government of India.

|-
|| 12:01
|| This is Himanshi Karwanje from IIT-Bombay.

Thank you for joining.
|-
|}

Apps-On-Physics/C3/Magnetism-and-Electromagnetism/English-timed - Revision history

PoojaMoolya: Created page with "{|border=1 |- || '''Time''' || '''Narration''' |- || 00:01 || Welcome to the Spoken Tutorial on '''Magnetism''' and '''Electromagnetism'''. |- || 00;07 || At the end of thi..."