Smt356 Videocassette 3

Synopsis

A: Introduces the idea of an electromagnetic wave and shows how a wave equation can be derived from Maxwell’s equations. Presents a scalar wave equation and its sinusoidal solution and illustrates various properties of the sine wave. Also shows D’Alembert’s solution. The second section reviews Faraday’s discovery that a changing magnetic field produces an electric field. Illustrates Maxwell’s idea of displacement current, which shows that a changing electric field produces a magnetic field. These two effects are the essence of an electromagnetic wave. A wave equation is derived from Maxwell’s equations.
B: Looks at the work of Heinrich Hertz, the 19th-century German physicist whose insight into the meaning of the Maxwell theory of electricity and magnetism opened up a new range of frequencies in the electromagnetic spectrum. Uses replicas of Maxwell’s equipment to explain and demonstrate his work.
C: Investigates two important properties of electromagnetic waves: plane-ness and polarisation, and shows how plane polarised waves can be used to model real-world phenomena.
D: Describes how electromagnetic waves are absorbed and attenuated as they pass through metals.
E (21 min): BBC Outside Broadcasts (OB) relays live pictures into millions of homes. How do the pictures get there? Part 1 explores the route taken by the signals: via co-axial cables to the control vehicle, by microwave from dish to dish via repeater stations in sight of each other, and eventually to the Crystal Palace TV mast. Crystal Palace functions as both a transmitter and a receiver for OB signals. The received signals, passing down the mast to the ‘links room’ en route to the studio for eventual broadcast, travel alongside the broadcast signal coming up en route to the domestic receiver. The film looks at the electromagnetic aspects of the journey - choice of medium and specific frequencys used. Part 2 examines the part played by waveguides in steering the signals at specific stages of their journey abd discusses the relationship between frequency and information-carrying capacity.

Series

Electromagnetism, Course Smt356

Language

English

Country

Great Britain

Medium

Video; Videocassette. VHS. col. 91 min.

Year of production

1991

Availability

Sale; 1999 sale: £120.00 (+VAT +p&p)

Documentation

Accompanying booklet.

Subjects

Physics

Keywords

electromagnetism; Hertz, Heinrich; television technology

Sections

Title

Electromagnetic waves

Title

Band A

Title

Hertz: putting Maxwell to the test

Title

Band B

Title

Plane polarized waves

Title

Band C

Title

Absorption of electromagnetic waves

Title

Band D

Title

Putting waves guides to work

Title

Band E

Production Company

Name

BBC Open University Productions

Distributor

Name

Open University Worldwide

Web

http://www.ouw.co.uk External site opens in new window

Phone

+44 (0) 1908 274066

Address

Walton Hall
Milton Keynes
MK7 6AA

Notes

NB. As of May 2016 Open University Worldwide are no longer distributing DVDs. They have posted this message on their website: ‘Unfortunately Open University Worldwide Limited has decided that product sales are no longer viable given the reduced funding to Higher Education institutions and diminishing demand for the products we have traditionally stocked. At present the Open University Students Association (OUSA) will continue to sell the "Good Study Guide", and we are in discussion with other possible distributors to continue to make The Open University’s products available for purchase. As soon as we have any information on other channels of distribution we will update this notice’. Some products are still available via second hand dealers on Amazon.co.uk