Consider two copper wires with circular cross-sections and equal ...

[serike]

Consider two copper wires with circular cross-sections and equal lengths. One wire has 3 times the diameter of the other. How do the resistances of these two wires compare?
 
  A) The thicker wire has 1/3 the resistance of the thinner wire.
  B) The thicker wire has 1/9 the resistance of the thinner wire.
  C) The thicker wire has 3 times the resistance of the thinner wire.
  D) The thicker wire has 9 times the resistance of the thinner wire.
  E) The thicker wire has times the resistance of the thinner wire.

Question 2

How much thermal energy is required to raise the temperature of a 225-g lead ball from 15.0C to 25.0C? The specific heat of lead is 128 J/kg  K.
 
  A) 725 J
  B) 576 J
  C) 145 J
  D) 217 J
  E) 288 J

[isabelt_18]

Answer to Question 1

B

Answer to Question 2

E

[serike]

TYSM

[jackie]

Gracias!