i will tell you how if you tell me what this project is called,it uses light bulb, copper wires,holder,6 volt battery.
if the copper wire (s) were conneting the battery to the lamp removing one of the wires would break a circut and the lamp goes out.
copper
Answer why does the person who made a circuit a probably connect the wires to a penny
Yes. You can twist them together and wire nut them, or solder them together.
At the battery if at all possible.
Because copper can connect one thing to another so there are multiple wires to connect multiple things
If you mean 2 bare copper wires those are the ground wires. Tie them together and then connect the light fixture ground wire which will be green or bare copper to those ground wires.
open
The two wires which connect the timer switch on a Century 87423 battery charger are the red and black wires. The red goes to the positive connector while the black goes to the negative connector.
connect the power and acc wires together and put them on the positive and the ground to the negative
The copper wires used connect. Because conductivity of Cooper higher than aluminium but price of Cooper higher than aluminum. If compare between copper and aluminium cable can see at the same current rate diameter of aluminium cable is larger than copper cable.
Disconnect the battery, and remove the spark plug wires one by one. Replace the spark plug wires in the same order, ensure the connection is firm, and connect the battery.