Author Question: An electric device, which heats water by immersing a resistance wire in the water, generates 50 cal ... (Read 90 times)

V@ndy87 · **on:** Jul 28, 2018

An electric device, which heats water by immersing a resistance wire in the water, generates 50 cal of heat per second when an electric potential difference of 12 V is placed across its leads. What is the resistance of the heater wire? (Note: 1 cal = 4.186 J)
a. 0.94 W
b. 0.81 W
c. 0.58 W
d. 0.69 W
e. 1.5 W

Question 2

In the Drude model of electrical conduction, the current density is directly proportional to
a. the average time interval between successive collisions.
b. the number of charge carriers per unit volume. c. the square of the electron charge. d. the electric field present in the wire. e. the product of all four quantities listed above.