Why is cathode in a galvanic cell considered to be positive electrode ?

Explanation

(1) According to IUPAC conventions, the electrode of the galvanic cell where electronation or reduction taks place is called cathode. In this, the electrons from metal electrode are removed by cations required for their reduction.
`Cu_((aq))^(2+)+2e^(-)rarr Cu_((s))`
(2) Since the electrons are lost, the metal electrode acquires a positive charge.
Hence cathode in the galvanic cell is considered to be positive.