Author Question: Jadeen says that you can increase the resistance of a copper wire by hammering the wire to make it ... (Read 158 times)

jerry coleman · **on:** Jul 28, 2018

Jadeen says that you can increase the resistance of a copper wire by hammering the wire to make it narrower and longer. Arnell says that you can increase its resistance by heating the wire. Which one, if either, is correct, and why?
a. Arnell, because the conductivity of the wire increases when it is heated. b. Arnell, because the conductivity of the wire decreases when it is heated. c. Jadeen, because the conductivity of a wire is directly proportional to its area and inversely proportional to its length.
d. Jadeen, because the conductivity of a copper wire does not increase when it is hammered. e. Both are correct because (b) and (d) are both correct.

Question 2

Light bulb A is rated at 60 W and light bulb B is rated at 100 W. Both are designed to operate at 110 V. Which statement is correct?
a. The 60 W bulb has a greater resistance and greater current than the 100 W bulb. b. The 60 W bulb has a greater resistance and smaller current than the 100 W bulb. c. The 60 W bulb has a smaller resistance and smaller current than the 100 W bulb. d. The 60 W bulb has a smaller resistance and greater current than the 100 W bulb. e. We need to know the resistivities of the filaments to answer this question.