Yes, this can be done.
It can be if you connect two same watt lamps in series with each other. The 240 volt supply will drop 120 volts across each lamp.
You can't. All you can do is install a new fixture that will allow higher wattage lamps.
Different lamps do different specific applications. Any lamp can be changed into any fixture as long as the fixture's wattage rating is not exceeded.
These terms mean the same thing: typically people say 'bulbs', 'lights', or 'lamps'. Most electricians use 'lamps' to mean any of these. Typically, a light fixture is called a fixture, or a luminaire. The part that actually lights, is called a lamp. (A table lamp can also be called a lamp).
Yes
No. Only replace lamps in a fixture that the manufacturer of the fixture recommends. By installing larger than recommended lamps this could create a fire due to the increase of heat generated by the over size lamp.
In electrical terminology bulbs and lamps are the same thing. If you are talking about a lamp as a fixture no bulbs and lamp fixtures do no need to be sold together.
If you are referring to house wiring, then you don't normally connect lamps in series with each other; they are normally connected in parallel with each other. When lamps are connected in parallel, each lamp is subjected to the same voltage; providing this is the rated voltage of each lamp, them each will operate at their rated power.If you did connect lamps in parallel, the you would find that the lamps with the higher power ratings will be dimmer than the lamps with the lower power ratings -which is not what you might expect!
Not necessarily. It's the wattage of the lamps that determine how much power is used. 277V lighting merely allows for more lights to be on a circuit than if they were on a 120V. The current that is printed on the ballast, times the voltage the ballast is connected to, is what determines the cost to operate the fixture. This is the true wattage of the fixture. The wattage of the lamps are independent as new electronic ballasts can power a numerous amount of tubes of various wattages.
Depends on the ballast most of the newer electronic ones work on a wide range of lamps and input voltages and one or two lamps
No, it is not recommended to use a T5 lamp in a T4 fixture. T5 lamps are designed to work with T5 fixtures, which have different dimensions and electrical requirements compared to T4 fixtures. Using a T5 lamp in a T4 fixture can lead to compatibility issues and may cause damage to the fixture or lamp.
That would depend upon the voltage of the lamps. Heat lamps in a bath are usually 110 volts AC. You also need to know the wattage of the lamps. That will determine the capacity (think number of lamps) that the circuit could support. These ratings can be found on the lamp itself. The fixture supporting the lamp must also be of the correct capacity.