In another test, the 10 heaters are exchanged for 5 larger heaters that each use a current...

In another test, the 10 heaters are exchanged for 5 larger heaters that each use a current of 20 A from an 800-V power supply. What is the total power usage of the 5 new heaters?

A.     16 kW

B.      32 kW

C.      80 kW

D.     320 kW

Read the paragraph and then answer the following questions:

The diagram shows a small water heater that uses an electric current to supply energy to heat water. A heating element. RL, is immersed in the water and acts as a 1.0-i2 load resistor. A dc source is mounted on the outside of the water heater and is wired in paral­lel with a 2.0-£2 resistor ( Rs) and the load resistor. When the water is being heated, the current source supplies a steady current ( R) of 0.5 A to the circuit. The water heater has a heat capacity of C and holds 1.0 × 10-3 m3 of water. The water has a mass of 1.0 kg. The entire system is ther­mally isolated and designed to maintain an approximately constant temperature of 60°C. [ Note: The specific heat of water ( cw) = 4.2 x 103 J/(kg °C).]