View source for PhET-Simulations-for-Physics/C3/Faraday’s-Electromagnetic-Lab/English

{|border=1
||'''Visual Cue'''
||'''Narration'''
|-
|| '''Slide Number 1'''

'''Title slide'''
|| Welcome to this spoken tutorial on '''Faraday's Electromagnetic Lab'''.

|-
|| '''Slide Number 2'''

'''Learning objectives'''
|| In this tutorial, we will demonstrate, 

'''Faraday's Electromagnetic Lab PhET simulation'''.

|-
|| '''Slide Number 3'''

'''System Requirements'''
|| Here I am using-

Ubuntu Linux OS version 14.04

Java version 1.8.0

Firefox web browser version 61.0.1

|-
|| '''Slide Number 4'''

'''Pre-requisites'''
|| To follow this tutorial,

Learner should be familiar with topics in high school Physics.

|-
|| '''Slide Number 5'''

'''Learning Goals'''
|| Using this simulation we will be able to,

* Predict the change in magnetic field as the magnet moves
* Study the deflections of compass with respect to the magnetic field
* Compare the change in voltage with an induced '''EMF'''
|-
|| '''Slide Number 6'''

'''Learning Goals'''
|| 
* Explain the cause of electromagnetic induction
* Explain the working of a '''transformer'''
* Show how a '''generator''' works
|-
|| 
|| For more information please see the additional material provided along with this tutorial.

|-
|| '''Slide Number 7'''

'''Link for PhET simulation'''

[http://phet.colorado.edu/ http://phet.colorado.edu]
|| Use the given link to download the '''simulation'''.

[http://phet.colorado.edu/ http://phet.colorado.edu]

|-
|| Point to '''faraday_en.jar'''.
|| I have already downloaded '''Faraday's Electromagnetic Lab simulation''' to my '''Downloads''' folder.

|-
|| To open java file,

Press '''Ctrl+Alt+T''' keys.

Type '''cd Downloads''' >> press '''Enter'''.
|| To run this '''simulation''', open the terminal.

At the prompt type '''cd Downloads''' and press '''Enter'''.

|-
|| Type '''java -jar faraday_en.jar''' >> press '''Enter'''.

Point to interface.
|| Now type, '''java space hyphen jar space faraday_en.jar''' and press '''Enter'''.

'''Faraday's Electromagnetic Lab simulation''' opens.
|-
|| Point to different tabs.
|| '''Simulation''' interface has five tabs.

'''Bar Magnet'''

'''Pickup Coil'''

'''Electromagnet'''

'''Transformer'''

'''Generator'''

|-
|| Point to the '''Bar Magnet''' tab.
|| By default '''Bar Magnet''' tab opens.

|-
|| Point to the bar magnet and compass.
|| On the screen we see, 

a bar magnet with north and south poles marked and a compass.

|-
|| Point to the lines of force.
|| Magnetic lines of force are seen spread across the screen.

|-
|| Point to the visual cue.
|| A visual cue '''Move me or me''' is also seen.

This visual cue prompts us to drag the magnet or the compass. 
|-
|| Cursor on the interface.

Point to magnetic lines of force.
|| Let us change the needle spacing and needle size.

This helps us to view the magnetic lines of force clearly.

|-
|| Click on '''Options''' menu >> select '''Field Controls'''.

Point to the '''Field Controls''' dialog box.
|| Click on '''Options''' menu and select '''Field Controls'''.

'''Field Controls''' dialog box opens.
|-
|| Point '''Needle spacing''' and '''Needle size '''sliders.
|| In the dialog box, we have sliders for '''Needle spacing''' and '''Needle size'''.

|-
|| Drag the '''Needle spacing''' slider to 60 >> '''Needle size''' slider to 50x14.
|| Drag the '''Needle spacing''' slider to 60 and '''Needle size''' slider to 50x14(50 by 14).
|-
|| Highlight the changes. 
|| You can change the sliders as per your requirement.

|-
|| Click '''OK''' button.
|| Click on '''OK''' button and observe the changes.

|-
|| Drag the magnet around the screen.
|| Drag the magnet around the screen.

|-
|| Point to the magnetic field.
|| Note that, magnetic lines of force align and rearrange as we drag the magnet.
|-
|| Drag the compass around the magnet.

Point to compass needle.
|| Now drag the compass around the magnet.

Note that compass needle aligns according to the magnetic lines of force. 

|-
|| Point to the '''Bar Magnet Strength''' slider.

Cursor on the slider.
|| On the right panel, we have '''Bar Magnet Strength''' slider.

Slider can be set between 0 to 100 percent.
|-
|| Drag the slider to 0%.
|| At 0% strength we do not see any magnetic lines of force.

|-
|| Drag the slider 100%. 
|| As we drag the slider towards 100%, magnetic lines of force are seen clearly. 

|-
|| Click on '''Flip Polarity''' button.
|| Click on '''Flip Polarity''' button on the right panel.

|-
|| Point to the magnet.
|| Polarity of the magnet changes.
|-
|| Point to field lines and compass needle.
|| Change in polarity changes the direction of lines of force and compass needle.

|-
|| Click on '''See Inside Magnet''' check box in the right panel. 

Point to the lines.
|| Click on '''See Inside Magnet''' check box in the right panel. 

Observe the direction of lines of force inside the magnet.

|-
|| Click on '''Show Field Meter''' check box. 
|| Click on '''Show Field Meter''' check box in the right panel. 

|-
|| Point to '''field meter'''.
|| '''Field meter''' shows up on the screen.

|-
|| Drag the '''Field meter''' around the field.

Point to the values of '''B''', '''Bx''', '''By''' and '''Ө'''.
|| Drag the '''Field meter''' around the field.

It displays the changing values of,

Magnetic flux density '''B''', x component of B('''Bx'''), y component of B('''By''') and angle of deflection('''Ө''').

|-
|| Click on '''Pickup Coil''' tab.

Cursor on the interface.
|| Now click on '''Pickup Coil''' tab.

This screen demonstrates '''Faraday's law of Electromagnetic induction'''.

|-
|| Point to magnet and a coil.

Point to the bulb.
|| '''Pickup Coil''' screen has a magnet and a coil connected to a bulb.

'''Pickup Coil''' panel is added to the right panel.

The bulb acts as an '''indicator''' in the circuit.
|-
|| Move and show.
|| Here we can either drag the magnet towards the coil or coil towards the magnet.
|-
|| Drag the magnet towards the coil.
|| The most effective way is to drag the magnet towards the coil.

This is because, moving a magnet induces magnetic field around the coil.

|-
|| Drag the magnet back and forth through the coil.

Point to the bulb.
|| Let us drag the magnet back and forth through the coil.

Observe that bulb glows.

|-
|| Point to changing magnetic field.
|| This is due to the induced '''EMF''' in the coil.

This creates changing magnetic field around the coil.

|-
|| Click on '''Loops''' input box>> increase the number of loops to 3.
|| Now let us increase the number of loops to 3 in the '''Loops''' input box.

|-
|| Drag the '''Loop Area''' slider to 100.
|| Then drag the '''Loop Area''' slider to 100%.

|-
|| Drag the magnet through the loop.

Point to the bulb.

Point to the bulb.
|| Drag the magnet through the loop.

Observe the glow in the bulb.

The intensity of the bulb changes as we drag the magnet.

|-
|| '''Slide Number 8'''

'''Assignment'''
|| As an assignment,

Replace the bulb with voltage meter.

Observe the change in the induced '''EMF''', when

1. Magnet is moved rapidly 

2. Polarity of the magnet is flipped

Explain your observation.

|-
|| Click on '''Electromagnet''' tab.
|| Click on '''Electromagnet''' tab.

|-
|| Point to electromagnet, magnetic lines of force and compass.
|| This screen has an electromagnet with its magnetic lines of force and a compass.

|-
|| Point to 10 v battery.

Point to voltage slider.
|| Electromagnet has a 10 v battery as a source of current.

This Battery has a voltage slider to control the voltage.

|-
|| Point to '''DC Current Source'''.
|| By default electromagnet has '''DC Current Source'''.

|-
|| Point to magnetic field.
|| Here '''DC''' electromagnet creates a constant magnetic field.

|-
|| Check '''Show Field Meter''' check-box.

Place the '''field meter''' on the coil.
|| Click on '''Show Field Meter''' check-box.

Place the '''field meter''' on the coil.

|-
|| Drag the voltage slider towards zero.

Point to electrons.
|| Gradually decrease the voltage of the battery from 10 volt to 1 volt. 

Observe the change in speed of electrons on the coil with change in voltage.
|-
|| Point to electron movement.
|| The speed of electron movement decreases as voltage is reduced from 10 volt to 1 volt.
|-
|| Point to magnetic field lines.
|| Magnetic field disappears at zero voltage.

Now, the coil is no more an electromagnet.

|-
|| Drag the slider to left side towards 10 v.
|| Continue to drag the voltage slider to the left side towards 10 volt.
|-
|| Point to compass needle.
|| Polarity of electromagnet has changed.

This changes direction of magnetic lines of force.

|-
|| Point to electrons.
|| Notice the change in direction of movement of electrons.

|-
|| Point to '''DC''' and '''AC'''.

Click on '''AC current source'''.
|| Now let us switch the '''DC current source''' to '''AC'''.

|-
|| Point to field meter and compass needle.
|| Observe the continuously switching magnetic field and compass needle.

|-
|| Point to two sliders.
|| '''AC Current Supply''' is provided with two sliders.

|-
|| Drag the horizontal slider.

Point to magnetic field lines and meter.

Point to the Amplitude slider.
|| Drag the horizontal slider to change the frequency of the wave.

Note that rate of magnetic field switching has increased.

Drag the vertical slider and check what happens?
|-
|| '''Slide Number 9'''

'''Assignment'''
|| As an assignment,

Change the number of loops of the coil 

and observe the magnetic field(B) values.
|-
|| 
|| Let us see how a '''transformer''' works.

|-
|| Click on '''Transformer''' tab.
|| Click on '''Transformer''' tab to open it.

|-
|| Point to '''Electromagnet'''. 

Point to '''Pickup Coil'''.
|| '''Transformer''' screen has, 

* an electromagnet with '''DC''' current source as a primary coil

* a '''Pickup Coil''' with '''Indicator''' as a secondary coil
|-
||Point to both the coils.
|| In the '''transformer''', primary coil induces a current into a secondary coil.

|-
|| Point to '''Electromagnet''' and '''Pickup Coil''' boxes.
|| Right panel has '''Electromagnet''' and '''Pickup Coil''' boxes.

|-
|| Click on '''Show Compass''' check-box.
|| Click on '''Show Compass''' check-box in '''Electromagnet''' box.

|-
|| Cursor on interface.

Drag the coils close to each other.
|| In a '''transformer''', two coils are linked together by an iron core.

However, in this case we don't have the iron core to link the coils.

Move the coils close, so that they touch each other.

|-
|| Point to area of the loop.

Point to light bulb.
|| At the stationary position there is no change in the flux.

Hence, bulb does not glow.

|-
|| Point to the secondary coil.
|| To induce voltage in the secondary coil, magnetic field should vary.

|-
|| Drag the slider to left side.

Point to light bulb.

Point to compass needle and electrons.
|| Drag the voltage slider of the electromagnet back and forth.

As we drag, notice that bulb glows.

Also, note the deflections in the compass needle and direction of flow of electrons.

|-
|| Move primary coil in and out of the secondary coil.

Point to area of loop.

Point to light bulb.
|| Next drag the primary coil in and out of the secondary coil.

Observe the change in flux as we move the coil.

Now bulb glows brightly.
|-
|| Point to '''Electromagnet''' box.

Click on '''AC''' source.
|| From the '''Electromagnet''' box, change the '''DC''' source to '''AC''' source.

|-
|| Point to magnetic field lines.

Point to the secondary coil.
|| '''AC''' current in primary coil produces a changing magnetic field.

This changing magnetic field induces a voltage in the secondary coil.

|-
|| Point to light bulb.
|| Observe the change in voltage in the bulb with changing magnetic field.

|-
|| Drag the vertical slider of AC current supply.

Point to light bulb.
|| In the '''AC''' current supply, increase the amplitude.

With the increase in amplitude of the wave, bulb glows brightly.
|-
|| Drag the horizontal slider.
|| Drag the horizontal slider to increase the frequency.

|-
|| Point to light of light bulb and compass needle.
|| Notice the fast flickering in the bulb and deflections on compass.

This is due to change in voltage in the coils.

|-
|| Point to coils of primary and secondary coil.
|| Note that there are 4 loops on the primary coil and 2 loops on the secondary coil.

|-
|| Under '''Pickup Coil''' box, 

Click on '''Loops''' input box >> increase the number of loops to 3.

Under '''Electromagnet''' box, Reduce the number of loops to 1.
|| Now increase the number of loops on secondary coil to 3. 

Reduce the number of loops of primary coil to 1.
|-
|| Point to light bulb.
|| Note the change in voltage of the bulb in the '''transformer'''.

|-
|| '''Slide Number 10'''

'''Assignment'''
|| As an assignment,

Check what happens when frequency slider of '''AC Current Supply''' is moved to 5%?

Explain your observation.

|-
|| Point to '''Generator'''.
|| Now we will move on to '''Generator'''.

|-
|| Click on '''Generator''' tab.

Point to left side of the screen.
|| Click on '''Generator''' tab to open it.

This is a simple version of a '''generator'''.

|-
|| Point to the tools on the right side of the screen.
|| On the right panel, we have '''Bar Magnet''' and '''Pickup Coil''' boxes.

|-
|| Click on '''Show Field''' >> '''Show Field Meter''' check-boxes.
|| Under the''' Bar magnet''' box, click on '''Show Field''' and '''Show Field Meter''' check-boxes.

|-
|| Point to faucet, paddlewheel with bar magnet, '''pickup coil''', compass and '''Field Meter'''.
|| Screen has a faucet, paddlewheel with a bar magnet, '''pickup coil''', compass and '''Field Meter'''.

|-
|| Point to bar magnet.
|| By default the Bar magnet is at '''0 RPM''' (revolutions per minute).

|-
|| Drag, place '''Field Meter''' close to coil.
|| Drag and place the '''Field Meter''' close to the coil.

|-
|| Drag slider at the top of tap.
|| Drag the slider to turn on the faucet.

|-
|| Point to rotating bar magnet.

Point to changing magnetic lines.

Point to compass.
|| Observe that the bar magnet starts spinning as water falls on it.

As the magnet rotates, magnetic lines of force change continuously.

|-
|| Point to '''Field Meter''' and compass.
|| Notice the change in the values in the '''Field Meter'''.

|-
|| Point to light bulb.
|| This results in the production of induced '''EMF''' in the coil and bulb glows.

|-
|| Point to '''RPM''' value.
|| Now lets increase the rotation of magnet to '''100 RPM'''.

|-
|| Drag the faucet slider to the extreme right end.
|| Drag the faucet slider gradually to maximum.

|-
|| Point to magnetic field lines.
|| Observe the rapidly changing magnetic field with increase in '''RPM'''.

|-
|| Point to light bulb.
|| Now bulb glows brightly as the voltage increases.

|-
|| 
|| Pause the tutorial and do this assignment.

|-
|| '''Slide Number 11'''

'''Assignment'''
|| What changes do you see in the working of the '''generator''', when

1. Number of loops and loop area of the wire are changed.

2. Bar magnet strength is reduce to 0%?
|-
|| 
|| Let us summarise.

|-
|| '''Slide Number 12'''

'''Summary'''
|| In this tutorial we have demonstrated,

How to use '''Faraday's Electromagnetic Lab, PhET simulation'''.

|-
|| '''Slide Number 13'''

'''Summary'''
|| Using this '''simulation''' we have,

Predicted the change in magnetic field as the magnet moves.

Studied the deflections of compass with respect to the magnetic field.

Compared change in voltage with induced '''EMF'''.

|-
|| '''Slide Number 14'''

'''Summary'''
|| Explained the cause of electromagnetic induction.

Explained how a '''transformer''' works.

Shown how a '''generator''' works.

|-
|| '''Slide Number 15'''

'''About Spoken Tutorial project'''
|| The video at the following link summarizes the Spoken Tutorial project.

Please download and watch it.

|-
|| '''Slide Number 16'''

'''Spoken Tutorial workshops'''
|| The '''Spoken Tutorial Project '''team:

conducts workshops using spoken tutorials and

* gives certificates on passing online tests.

For more details, please write to us.

|-
|| '''Slide Number 17'''

'''Forum for specific questions:'''

Do you have questions in THIS '''Spoken Tutorial'''?

* Please visit this site

* Choose the minute and second where you have the question

* Explain your question briefly

* Someone from our team will answer them

|| Please post your timed queries in this forum.

|-
|| '''Slide Number 18'''

'''Acknowledgements'''

|| This project is partially funded by Pandit Madan Mohan Malaviya National Mission on Teachers and Teaching.

|-
|| '''Slide Number 19'''

'''Acknowledgement'''
|| Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India.

More information on this mission is available at

this link.

|-
|| 
|| This tutorial is contributed by Madhuri Ganapathi and Meenal Ghoderao from IIT-Bombay.

Thank you for joining

|}