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The Electric Bell | Grade: 08th

Electric Bell: Concept Working Principle of the Electric Bell:

The working principal is as follows: 1. Once the battery is connected a current flows in the wire loops around the soft iron core. This turns the core into an Electromagnet.

As we know, an electromagnet is formed by coiling multiple turns of insulated wire around a magnetic substance such as soft iron. When we run current through such an electromagnet, this soft iron behaves like a magnet. This is the principal behind the electric bell. Lets use this science concept to build an electric bell!

2. The electromagnet attracts the hammer which is also made of soft iron. 3. As the clapper moves towards the electromagnet, it causes the hammer to strike the bell. At the same time it breaks the circuit at X.

The basic Electric Bell is designed as shown in the diagram in the centre. The Electromagnet consists of a Solenoid (coil made of

hundreds of turns of copper wire) with an iron Core passing through it.

4. The break in the circuit causes the current to stop flowing. The soft iron cores loses it’s magnetic field and releases the armature which springs back to it’s original position.

The Electric Bell | Grade: 08 |


5. When the armature goes back to its original position, the contact screw touches the springy metal and completes the circuit, creating an electromagnet that again attracts the armature, and the armature hammer once again strikes the bell. The whole cycle is repeated over, causing the bell to ring continuously until the battery is disconnected.

A solenoid (from the French solénoïde, derived in turn from the Greek solen "pipe, channel" + combining form of Greek eidos "form, shape" is a coil wound into a tightly packed helix. The term was invented by French physicist André-Marie Ampère to designate a helical coil. In physics, the term refers specifically to a long, thin loop of wire, often wrapped around a metallic core, which produces a uniform magnetic field in a volume of space (where some experiment might be carried out) when an electric current is passed through it. Solenoids are important because they can create controlled magnetic fields and can be used as electromagnets.

Fun Facts: Did you know that there is another type of Bell called the Oxford Bell that operates on the principle of Electrostatics. Although it did not become popular like the Electric Bell, there is an Oxford Bell that has been ringing continuously since 1840! This bell is at the Oxford University, England.

The Electric Bell | Grade: 08 |


Electric Bell: The Making of it! What we need ?

1. Solenoid

2. Clapper

3. 9v Cell

4. Connecting wires and Crocodile Clip

5. Bell 6. Screw Holder

9. Nut & Bolt

7. Battery Stand

8. Signage

10. Assembly Base

The Electric Bell | Grade: 08 |


Electric Bell: Assembly Step: 01 Place the Assembly Base on tflat surface

Step: 02 Tighten the solenoid over it with the help of nut.

Step: 03 Plug in Battery stand + Screw Holders + Bell Hanger on the place

Step: 04 Fix the clapper with nut and screw at holder A. Insert the Battery in the stand.

The Electric Bell | Grade: 08 |


Step: 05 Connect the wire with the help of crocodile clip as shown below in the dia-

Step: 06 Fine tune the screw B to make it touch clapper softly to complete the circuit.

Step: 07 Fine tune the Bell. Adjust the distance between wobbling clapper to ring the bell

Excercise Complete. Cheers!

The Electric Bell | Grade: 08 |


Manoj T. Founder

Vinod A. Founder

CURIOSITI: THE ELECTRIC BELL Grade: VIII First Edition 2013 Head Office # **/*, 27th Main, HSR Laout, Bangalore 560102 Regional Office Kolkata, Delhi, Chennai, Mumbai International Office Opposite of 1 Infinity loop USA Š CURIOSITI, 2013

Design Partner

Anshuman Kumar Bangalore, India Printed in India at Xxxxx xxxx xx, xxxxxxxx Bangalore xxxxxx

Curiosity electric bell