Final answer:
The receptor found on the postsynaptic cell in a neuromuscular junction is the nicotinic acetylcholine receptor. This receptor is responsible for muscle contraction.
Step-by-step explanation:
The receptor found on the postsynaptic cell in a neuromuscular junction is the nicotinic acetylcholine receptor. This receptor is specific to the neurotransmitter acetylcholine and is responsible for initiating muscle contraction in response to nerve impulse.