ExpEYES/C2/Electro-Magnetism/English-timed

Time	Narration
00:01	Hello everyone. Welcome to this tutorial on Electro-magnetic induction.
00:06	In this tutorial we will demonstrate: Electro-magnetic induction Mutual induction of coils Voltage induced by a rotating magnet Resonance of driven pendulum. And show circuit diagrams for our experiments.
00:26	Here I am using, ExpEYES version 3.1.0 Ubuntu Linux OS version 14.10
00:35	To follow this tutorial, you should be familiar with ExpEYES Junior interface. If not, for relevant tutorials, please visit our website.
00:47	Let's begin with demonstration of Electro-magnetic Induction.
00:52	In this experiment, wires of 3000 turns coil are connected to ground(GND) and A1.
01:00	To show the magnetic effect, a magnet with 5mm diameter and 10mm length is used. This is the circuit diagram.
01:11	Let's see the result on the Plot window.
01:15	A horizontal trace appears on the Plot window. Roll a paper and insert it inside the coil.
01:23	Drop the magnet inside the rolled paper and move it up and down.
01:29	Repeat the process until the induced voltage is captured and displayed.
01:35	On the Plot window click on Experiments button.
01:39	Select Experiment list appears.Click on EM Induction.
01:46	Two new windows, Electromagnetic Induction and Schematic appear. Schematic window shows the circuit diagram.
01:56	On the Electromagnetic Induction window, click on Start Scanning button.Horizontal trace changes to a wave.
02:05	It happens when the periodic scanning of the voltage coincides with the movement of the magnet.
02:12	This indicates voltage is induced in the coil by a moving magnet.
02:18	Next I will demonstrate mutual induction of two coils.
02:23	In this experiment A2 is connected to SINE.SINE is connected to ground(GND) through a coil.
02:31	And A1 is connected to ground(GND) through a coil.This is the circuit diagram.
02:37	Let's see the result on the Plot window.
02:40	Click on A1 and drag to CH1.A1 is assigned to CH1.
02:47	Click on A2 and drag to CH2.A2 is assigned to CH2.
02:55	Move the msec/div slider to view applied waveform and induced waveform.
03:02	A changing magnetic field causes induced voltage.You may not see any induced voltage on the secondary coil.
03:12	Keep the coils close to each other along the axis.Insert some ferromagnetic material along the axis.
03:20	We have inserted a screw driver to induce voltage on the secondary coil.
03:26	Click and drag CH1 to FIT.Click and drag CH2 to FIT.
03:34	Voltage and frequency of A1 and A2 is seen on the right. Difference in the voltages of A1 and A2 is due to the induced voltage on the secondary coil.
03:47	Next we will demonstrate voltage induced by a rotating magnet using DC motor and coils.
03:56	In this experiment, A1 is connected to ground(GND) through a coil. SQR2 is connected to ground(GND) through a DC motor.
04:06	A permanent magent of 10mm diameter and 10mm length is mounted on DC motor. A2 is connected to ground(GND) through a coil.
04:18	This is the circuit diagram.
04:20	Let's see the result on the Plot window.
04:23	Under Setting Squarewaves, set the frequency value to 100Hz.Click on SQR2 checkbox.
04:34	Click on A1 and drag to CH1. A1 is assigned to CH1.
04:41	Click on A2 and drag to CH2.A2 is assigned to CH2.
04:47	Move the msec/div slider to obtain the wave form. Move the volt/div slider to adjust the wave form.
04:57	Click on CH1 and drag to FIT. Click on CH2 and drag to FIT.
05:05	On the right side you can see voltage and frequency.Please note, voltage and frequency values of the two alternating wave forms are almost the same.
05:16	This is because, as the magnet rotates, magnetic field around the coil constantly changes between the poles.
05:24	Rotation of the magnet results in alternating induced emf in the coil.
05:31	Next let's experiment with driven pendulum.
05:34	If a pendulum oscillates with an induced magnetic field it is called a driven pendulum
05:41	In this experiment, SQR1 is connected to Ground(GND) using a coil.
05:47	Button magnets are suspended in front of the coil with a paper strip as a Pendulum.This is the circuit diagram.
05:58	Let's see the result on the Plot window.
06:01	click on SQR1 check box.
06:05	Click on Experiments button.Select Experiment list appears.Select Driven Pendulum.
06:15	Two windows appear: Schematic of Driven Pendulum and EYES Junior: Driven Pendulum.
06:23	On the EYES Junior: Driven Pendulum window, drag the slider. As we drag the slider, the pendulum oscillates.
06:33	Between "2.6 Hz" to "2.9Hz" pendulum oscillates with a maximum amplitude. This is because its resonant frequency is same as its natural frequency.
06:47	Let's summarize.
06:49	In this tutorials we have learnt to demonstrate: Electromagnetic induction Mutual induction of coils Voltage induced by a rotating magnet Resonance of driven pendulum And Show circuit diagrams for our experiments.
07:09	As an assignment, demonstrate How to make an electromagnet. Mutual induction of a single coil with a magnet. Show circuit diagrams for the experiments.
07:22	This video summarises the Spoken Tutorial project If you do not have good bandwidth, you can download and watch it.
07:30	We conduct workshops using Spoken Tutorials and give certificates. Please contact us.
07:37	The Spoken Tutorial Project is funded by NMEICT, MHRD Government of India.
07:44	This tutorial is contributed by Kaushik Datta and Madhuri Ganapathi.Thank you for joining.

Contributors and Content Editors

Pratik kamble, Sandhya.np14