ExpEYES/C2/Electro-Magnetism/English-timed
From Script | Spoken-Tutorial
| 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 the 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 that 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 the 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 are 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 magnet 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 Square waves, set the frequency value to 100Hz. Click on SQR2 check-box. |
| 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 waveforms 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 tutorial, 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 induction of a single coil with a magnet Show circuit diagrams for the experiments. |
| 07:22 | This video summarizes 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. |
