|Samuel Hunter Christie, Charles Wheatstone electromagnetism|
- To measure resistance Rx, adjust the resistance R2
- until the voltage between the two midpoints (B and D) is zero
- and no current flows through the galvanometer Vg.
- You can calculate the unknown resistance Rx
- because the ratio of the resistances in the known leg ( R2 / R1 )
- is equal to the ratio of the resistances in the unknown leg ( Rx / R3).
- Samuel Hunter Christie invented it
- but Charles Wheatstone popularized it
- as though that was what mattered.
- Carey Foster bridge, to measure low resistances.
- Kelvin bridge, to measure four-terminal resistances.
- Maxwell bridge, to measure inductances.
- Diode bridge, also known as Graetz bridge,
- doesn’t measure anything.
- Tower Bridge, not the real London Bridge.
- Brooklyn Bridge, made famous by Hart Crane and not for sale.
- Tacoma Narrows Bridge, originally known as Galloping Gertie.
- Golden Gate Bridge
- whose cables contain 27,572 wires.