How many watts would I have consume?

Question

If I plug a 75 watts TV to a 150 watts transformer, will I be consuming 225 watts an hour for this appliance?

Answer 1

No

150 W transformer means the max output of that transformer is 150 watts

If you plug a TV you consume 75 Wh in one hour for the TV itself + a few watts per hour for the transformer (heat dissipation and such), so say 80 Wh give and take a little, depending on the efficiency of the transformer.