What type of current does a tv use? why do electric power plants not produce direct current? what type of current does a car battery provide?

TV sets could be built to work with either AC or DC.  Any TV that's
designed to be used in the house is built to plug into an outlet in the
wall, where it gets AC.

The power company wants to deliver as much as possible of the energy
it produces to customers who will pay for it, and wants to lose as little of it
as possible on its way to the customers. 
It turns out that the way to make the loss as small as possible is to move
the electrical energy through the wires with as high a voltage and as low
a current as possible.
That means the power company wants to send the energy over the cables
at thousands of volts, and then change it to 110 or 220 volts JUST before 
it goes into your house.
Transformers are used to change the voltage up and down.
Transformers ONLY work with AC.  They don't work with DC at all.
If the power company produced only DC, they would have to ship it out
at the same 110 volts that you would get from the outlets in your house,
even if it had to go through 100 miles of cables to reach your house.
The result would be that the cables might lose 10% or 15% of the energy
that the power company produced.  It would never reach the customers,
and it would be a big loss of money to the power company.  They would
have to raise the price of the electrical energy to make up the loss, and
everybody would wind up paying as much as 10% or 15% more for the
electricity they use in their house.

Batteries all produce direct current (DC).