The tube has wire filament heaters at each end like flashlight bulbs.The heaters glow when the light is switched on and ionise the gas inside.The ionised gas is subjected to a high voltage and a plasma ( like a lightning bolt) flows from end to end. The excited plasma causes the white powders on the inside of the glass to glow. When the filaments burn out they blacken the ends with metal oxide and it is then almost impossible to get the plasma started again without hot filaments glowing. 1-2000 volts would then be needed
In order to know why fluorescent bulbs turn black at the end, you need to understand how they work. Basically, when you turn on the lighht switch, the ballast sends a spark through the mercury-vapor-filled tube or bulb, depending on design. When it does this, it creates light by activating phosphors that coat the inside of the tube. Well each time the ballast fires, it creates emissions. These emissins materials then settle on the surface inside the glass. After awhile this material piles up. When it does this, the tube end turns completely black. Not only does the tube end turn black, but the accumulated materials pile up so high that it blocks the electrons that flow into the mercury. When this happens, you will notice the bulb or tube flicker heavily and then burn out.
The turns ratio is the number of primary turns divided by the number of secondary turns. This is the same ratio as input current to output current. ie the turns ratio N = I1/I2
For an ideal transformer, the voltage ratio is the same as its turns ratio.
600 volts is five times the 120 volt primary, so the secondary winding must have 750 turns, which is five times as many turns as the 150 turns of the primary winding.
If it's a step up or step down transformer and you know the secondary side current, multiply the secondary current by the turns ratio. If you know the power in the secondary winding but not the current, divide the secondary power by the secondary voltage to get the secondary current and then multiply the secondary current by the turns ratio to get the primary current. The turns ratio is the number of turns on the secondary winding divided by the number of turns on the primary winding. For a step up transformer, the turns ratio will be greater then one. If it's a step down transformer, then the turns ratio will be less than one. If you don't know the turns ratio, divide the secondary voltage by the primary voltage to get the turns ratio.
it turns black
It turns Black.
It is the black bird, launch then touch screen to detonate.
Iodine turns blue-black in the presence of starch.
It turns the iodine colour from brown to blue-black? This is because popcorn contains starch.
it is a yellowish/orange colour but when iodine is present, than it will turn an dark-blue/black colour
Iodine turns blue-black when it tests positive for starch due to the formation of a starch-iodine complex.
Briefly: Bleach is generally white therefore when used on something 'dirty' all the dirt and germs are an invisible white or transparent colour. When the white bleach is mixed with the black dirt (in most cases) then the colour of the bleach turns black because the dirt mixes with white. If you mix black paint with white it turns black or grey because dark overpowers white. hope this helps your random curiosity :)
in a variegated leaf only the green areas of the leaf turns blue black in colour when tested for starch what is the best way to explan that
The universal indicator turns blue or violet in alkaline solutions.
I did this lab experiment in my biology class. When Lugol's indicator is added to glucose, it turns to a dark green colour for starch it turns black and for surcose it turns yellow.
Orange. It turns colourless in acids and pink in alkaline.