Electrical Safety. Closed circuit. Open circuit. Electrical Safety. Fuse : a short piece of metal that melts if current exceeds a set value (to protect device) Circuit breaker : an automatic switch that opens the circuit when current exceeds a set value. (uses a bimetallic strip).
The brightness (Watts) of a light bulb depends on both the current going through the bulb and the resistance of the bulb filament.
Which one has a greater influence on the brightness- the current or the resistance?
Thicker wires can carry more current.
Thinner wires have more resistance.
So, which bulb has a thicker filament- a 40 W or a 100 W?
As electrons pass through these “semiconductors”, light is emitted
The electricity in your houses is alternating current, AC, not direct current, DC – as in batteries.
The main reason for this is that transformers can only step up or step down the voltage if it is alternating current.
Without transformers, there would be great loss of electrical power between the power stations and your houses. For electricity to be very efficient, there would have to be a power generating plant in EVERY community!
The electrons just wiggle back and forth.
In the US, they wiggle back and forth 60 times every second.
In other words, the frequency is 60 Hz.
Ferris designed and built the first 264 foot (80 meter) wheel for the World's Columbian Exposition in Chicago, Illinois in 1893. This first wheel was 26 stories tall and could carry 2,160 persons. There were 36 cars accommodating 60 people each (40 seated, 20 standing). It took 20 minutes for the wheel to make two revolutions - the first to make six stops to allow passengers to exit and enter; the 2nd a single non-stop revolution - and for that, the ticket holder paid 50 cents. The wheel was moved twice after the 1893 Fair and was eventually disassembled in 1906.