Question

If the current in the filament of a lamp is 3 A, the current in the connecting wire is?

A) less than 3 A.
B) 3 A.
C) more than 3 A.
D) not enough information to say.

Answer 1

B) 3 A

Explanation:

The filament and the connecting wires are connected in the circuit in series. For all components in series, the current through them is the same.

Take this circuit:

Note how all of the ammeters are displaying the same current regardless of where they are in the circuit, even the ones right next to the resistor. This is because in a series circuit, the current through each component is the same

Answer 2

3 A

Explanation:

Current is a flow of electrons. Current is measured in amperes (abbreviated amp or A). An amp flows in a wire if one coulomb of charge passes any point in the wire per second. That coulomb of charge would consist of many, many electrons (in fact, `6.25*10^18` electrons).

Electrons do not disappear. If an electron wearing a red hat enters a wire conducting a current of electrons, and if you watch long enough, you will see that electron with a red hat come to the other end of the wire. (I give you this as a way to picture what is going on. But it is not technically true. That electron may bump into an atom of the wire, and be captured. In which case another electron from that atom will be ejected.)

If the flow of current in the filament of a lamp is 3 A, it must be 3A in the wire bringing the current to the lamp.

I hope this helps,
Steve