Conductivity of Water
[M | t+ | ★★]
Add salt to water to make it conduct and light a bulb.
[In-Depth Description]
Conductivity of Copper
[M | t+ | ★★]
Light bulb gets brighter when copper leads are immersed in liquid N2 (positive temperature coeffient).
Conductivity of Glass
[M | t+ | —]
Insulating glass becomes a conductor of electricity when heated red-hot with a blowtorch. (m) (T+)
[In-Depth Description]
Conductivity of Carbon
[M | t+ | —]
Light bulb gets dimmer when carbon resistor (in series) is immersed in liquid N2 (negative temperature coefficient).
Conductivity of a Flame
[M | t | —]
An electroscope is discharged when a burning candle is brought near it.
Conductivity of Air
[M | t | —]
Electric conduction of air is demonstrated by Jacob's ladder.
IV Curves
[S/M | t+ | —]
A Tektronix "curve tracer" shows I vs V for resistor, germanium diode, silicon diode, or tunnel diode.
Hand Battery
[S | t | —]
Copper and zinc plates connected by micro-ammeter; your hand completes the circuit.
[In-Depth Description]
Lead Acid Battery
[M | t+ | —]
Homemade chemistry-lab style battery in a beaker.
[In-Depth Description]
Organic Battery
[M | t++ | —]
Use a selection of fruit to produce a voltage.
Piezo-electric Sparker
[M | t | —]
Generate high voltages by squeezing a crystal.
Bird on a High-Voltage Transmission Line
[M | t | ★★]
A model to help explain why birds don't get zapped on high-voltage transmission lines.
[In-Depth Description]
Thermo-electric Magnet
[M | t++ | —]
A large current-capacity thermocouple junction powers an electromagnet.
Lossy (or lousy) Transmission Line
[M | t | —]
Several light bulbs are wired in parallel; the resistance of the wire leads to appreciable I2R losses.
High Voltage Transmission Line
[M/L | t++ | —]
Power to a 100 W light bulb is transmitted throughhairlike wires; 15 kV step-up and step-down transformers do the trick.
OHP Circuit Board
[S | t | ★★★]
For construction of simple DC circuits.
[In-Depth Description]
DC Circuit Puzzlers to Ponder
[M | t | —]
Simple circuits with batteries, light bulbs, and switches challenge one's understanding.
[In-Depth Description]
Carbon Rod Microphone
[S | t+ | ★★]
Sound vibrations affect resistance between two carbon rods in contact with each other. Changes in current are amplified and made audible through loudspeaker.
Large Voltmeter/Ammeter Board
[L | t | —]
An application of series and parallel resistance circuits.
RL Time Constant
[L | t+ | ★★★]
Pre-assembled circuit board; displays RL time constant on CRO.
[In-Depth Description]
RC Time Constant
[L | t+ | ★★★]
Charging and discharging of a 10µF capacitor with variable time constant.
[In-Depth Description]
Contact Us
Mailing Address: Lecture Demonstration Services, Science Center, Rm B-08A, 1 Oxford Street, Cambridge, MA 02138
Campus Location: Science Center B-08A | Tel: (617) 495-5824 | Email: scidemos-at-fas.harvard.edu