What is it?
A device to kill disease causing microorganisms by using ultraviolet radiation ( short wavelength electromagnetic radiation).
Uses
Used in air and water filter systems.
Plasma globe
Inventor : Nikola Tesla
What is it?
A plasma lamp.
What is it made of?
A spherical transparent glass containing mixture of noble gases and a high voltage electrode at the center.
How does it work?
When a 3-5 kV alternative current of 35kHz is applied to the electrode, the gas in the globe ionizes which enables it to conduct electricity., current flows towards the glass.
The difference in electrical potential between the electrode and the atmosphere causes current to flow towards the glass.
The glass acts as dielectric and ionizes the atmospheric air molecules.
The excited ions in the globe de-excite by emitting photon.
Ultrasonic dishwasher
What is it?
A device to clean utensils.
What is it made of?
Ultrasonic transducer.
How does it work?
The dishes to be washed is kept immersed in water.
The ultrasonic sound waves produced inside water, vibrates the water molecules in ultrasonic frequency range.
Any impurity in contact with utensils comes off because of the push and pull effect of water molecules vibrating.
Stun gun
What is it?
It is a weapon to temporarily paralyze target by applying high voltage low current.
What is it made of?
It consists of battery, capacitor, step up transformer, oscillator and electrode.
How does it work?
The device generates high voltage low ampere current in the form of a pulse signal between the electrodes.
When the target comes in contact with both the electrodes the current flows which stuns the target (human).
Crookes Radiometer
Inventor : Sir. William Crookes
What is it?
Device to measure electromagnetic radiation.
What is it made of?
An airtight partial vacuum glass bulb with set of vanes mounted on a spindle through a frictionless rotor inside.
The vanes are equally spaced. One side of vane is black and the other side white.
How does it work?
When electromagnetic radiation is incident on the device, the region near white side of vane gets warmer than the black side of vane.
As white side reflects radiation, it warms the air molecules more than the black side which absorbs radiation.
These gas molecules move from cooler region to warmer region thus pushing the vane from white side to black side.
This phenomenon is called thermal transpiration.
Facts
It is also known as light mill.
It was an accidental invention.
The correct phenomenon of it’s working was discovered later.
Where can I get one?
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