A TTL circuit acts as current sink in

The correct answer is option 1):(low state and current source in high state.)

Concept:

• A TTL circuit acts as a current sink in the Low state
• The TTL input current is largest in low state.
• It describes how regular current travels from the positive, also known as the sourcing end, to the ground, known as the sinking end.
• Direct current often flows when two parts of a circuit source and sink current complete the circuit.