Question

How does the current flow through the copper wire change if we connect a copper wire of the same initial length to the same lenght as in the begining, but with twice the smaller radius?

a) the current is reduced by 2 times
b) the current increases twice
c) the current decreases 4 times
d) the current increases 4 times​

Answer 1

Step-by-step explanation:

The current flow through a wire is determined by the relationship between the voltage applied across the wire and its resistance. The resistance of a wire is directly proportional to its length and inversely proportional to the cross-sectional area (radius) of the wire.

If we connect a copper wire of the same initial length to another wire with twice the smaller radius, the cross-sectional area of the wire will change. Since the resistance is inversely proportional to the cross-sectional area, a decrease in the radius will result in an increase in resistance.

According to Ohm's Law (V = I * R), where V is the voltage, I is the current, and R is the resistance, if we keep the voltage constant, an increase in resistance will result in a decrease in current.

Therefore, the correct answer is:

c) The current decreases 4 times.