Two metal wires have the same length and cross-sectional area. Wire 1 is made of aluminum which has a resistance equal to a half the resistance of wire 2 at 20 degrees Celsius. The resistivity of the second wire 2 is a. 1.41 x 10^ -8 ohm*meter
b. 1.41 x 10^ -4 ohm*meter
c. 5.64 x 10^ -8 ohm*meter
d. 2.82 x 10^ -8 ohm*meter

What is meant by the statement" the melting poin of glycerine is 13 degree celsius

Apositive charge moves in the direction of an electric field. which of the following statements are true? check all that apply. check all that apply. 1.the potential energy associated with the charge decreases. 2. the electric field does positive work on the charge. 3. the electric field does negative work on the charge. 4. the potential energy associated with the charge increases. 5. the electric field does not do any work on the charge. 6. the amount of work done on the charge cannot be determined without additional information.

Aresistor with an unknown resistance is connected in parallel to a 9 ω resistor. when both resistors are connected in parallel to an emf source of 21 v, the current through the unknown resistor is measured with an ammeter to be 4 a. what is the resistance of the unknown resistor? answer in units of ω.