A loudspeaker is connected to an audio amplifier using a copper wire ( = 1.7 108 m) of 18 gauge (diameter 1.024 mm) of total length 20 m . (a) What is the resistance of the wire? (b) If the speaker has a resistance of 4, what percentage of the power supplied by the amplifier is dissipated in the wire? (For simplicity, assume that the potential difference does not vary with time and that the speaker is a resistor.)