What it shows:

Eddy currents set up in a copper paddle as it moves through a magnetic field oppose and dampen its motion. Slits cut into the paddle reduce the damping effect.

...

An empty aluminum soft drink can, placed inside a coil of wire, is made to implode when... Read more about Can Crusher - Magnetic Implosion

What it shows:

Oersted showed that an electric current produces a magnetic field. His experiment is repeated here on a suitable grand scale.

How it works:

The current carrying wire in...

A current carrying wire in a magnetic field experiences a force at right angles to both the field and current directions. The wire will jump up or down, depending upon the current direction.

Image on black and white television is deflected by a magnet, not unlike the Maltese Cross.

What it shows:
The television is basically a sophisticated cathode ray tube. The electron beam in the TV is influenced by magnetic fields in the same way as in Crookes tubes.

How it works:
The image on a black & white TV is formed by a single electron gun scanning the screen. Holding a strong magnet to the side or in front of the screen deflects the beam from its regular sweep pattern, distorting the image.

Setting...

Charging and discharging of a 10µF capacitor with variable time constant.

What it shows:

The growth and decay of current in an RC circuit with a time constant chosen so that the charge and discharge is visible in real time.

How it works:

By choosing the values of resistance and capacitance, a time constant can be selected with a value in seconds. The time constant τ is given by

τ = RC

To obtain useful values, we chose three resistors 100K, 200K and 400K in series with a 10µF capacitor, giving time constants of...

What it shows:

The growth and decay of current in an RL circuit with a time constant visible in real time.

How it works:

By choosing the values of resistance and inductance, a time constant can be selected with a value in seconds. The time constant τ is given by

τ = ^L/_R

We chose two resistance values, 4.7K and 10K coupled with a 45kH UNILAB ¹ induction coil giving time constants of 9.5sec and 4.5sec respectively.

The circuit is set out on a 1.0 × 0.5m plywood board. The actual...

What it shows:

A 2000 μF capacitor is discharged by a carbon steel wire. The surge of current literally vaporizes the wire and it explodes into a spectacular arc of sparks that span the front of the lecture hall.

How it works:

...

What it shows:

The basic principles of the parallel plate capacitor made large.

How it works:

The capacitance C of a simple parallel plate capacitor is given by


the ratio of the magnitude of the charge Q on either conductor...

What it shows:

A lecturer's faith in the principle that an electric field cannot exist inside a charged conductor is put to the test using a Faraday cage that is large enough to sit in.

How it works:

The lecturer (or some volunteer) climbs the three steps and sits upon a plain wooden chair. Their assistant pulls the mesh door closed and fastens it. A Van de Graaff, whose dome is in contact with the cage, begins to charge itself and the cage up to a high voltage. The person inside is oblivious to the large amount of charge now...

Two speakers, one at each end of rotating platform; beating due to frequency shift of speakers travelling in opposite directions.

What it shows:

Doppler shifting of sound to higher frequencies occurs when a source is moving towards the observer, and shifted to lower frequencies when the source is moving away. Here two sources emitting the same frequency when stationary rotate on a turntable. With one source moving towards you and one away, the Doppler shifted waves interfere to create beats.

How it works:

Two 1.5W 8Ω...

A bell, ringing in a bell jar, ceases to be heard as the bell jar is evacuated.

A pulse of sound gets "inverted" when reflecting off the open end of a pipe, but does not get inverted when reflecting off the closed end.

Standing sound waves in a glass pipe are made evident by the fountains of kerosene inside the pipe.

What it shows:

The air inside a very large glass pipe (partially filled with a fluid) is acoustically excited into a standing wave. Once resonating, the locations of the velocity antinodes inside the pipe are dramatically made evident by the vigorous agitation of the fluid, resulting in fabulous foaming frothing fountains of fluid. The velocity of sound can also be determined by noting the resonance frequency and measuring the distance between antinodes....