The potentiometer connected as a rheostat in Figure 1 is used to control the current to a...

The potentiometer connected as a rheostat in Figure 1 is used to control the current to a heating element. When the rheostat is adjusted to a value of 8 Ω or less, the heating element can burn out. What is the rated value of the fuse needed to protect the circuit if the voltage across the heating element at the point of maximum current is 100 V and the voltage across the rheostat is the difference between the heating element voltage and the source voltage?

Figure 3-24