It depends what the power rating of the appliance is. A 500 watt microwave will use half a kilowatt
Check the power rating of the TV, and multiply by how many hours you used it for. Say if it uses
that uses 1000 watts will use 1 kWh per hour; one that uses 100
watts will use 0.1 kWh per hour, etc.
Watts does not have a time component to it; so you should have asked, "How many kilowatt-hours