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When a voltage difference is applied to a piece of metal wire, a current flows through it. If this metal wire is now replaced with a silver wire having twice the diameter of the original wire, how much current will flow through the silver wire? The lengths of both wires are the same, and the voltage difference remains unchanged. (The resistivity of the original metal is 1.68 × 10-8 Ω ∙ m, and the resistivity of silver is 1.59 × 10-8 Ω ∙ m.)
Depression
A mood disorder characterized by persistent feelings of sadness, hopelessness, and a lack of interest or pleasure in activities.
Acetylcholine
A neurotransmitter in the central and peripheral nervous systems that plays a key role in muscle activation and memory.
Muscle Contraction
The process in which muscle fibers shorten or lengthen, producing movement or maintaining posture.
Neurotransmitter
Chemicals in the nervous system that transmit signals across a chemical synapse from one neuron (nerve cell) to another 'target' neuron.
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