By varying the rheostat (variable resistor) in the circuit of Figure 1, you can change the...

By varying the rheostat (variable resistor) in the circuit of Figure 1, you can change the amount of current. The setting of the rheostat is such that the current is 750 mA. What is the resistance value of this setting? To adjust the current to 1 A, to what resistance value must you set the rheostat? What is the problem with this circuit?

Figure 3-27