As shown in the figure is the circuit diagram of a household rice cooker, S1 is a temperature limit switch, by manual closure, when the temperature reaches 103 ℃ automatically disconnect, can not be a

As shown in the figure is the circuit diagram of a household rice cooker, S1 is a temperature limit switch, by manual closure, when the temperature reaches 103 ℃ automatically disconnect, can not be automatically closed.S2 is the (1) when the start of heating, S2 closed, R2 short circuit, the circuit only R1 access to the circuit, as shown in Figure 1.

The electrical power of the rice cooker:

P1=

U2

R1

=

(220V)2

50Ω

=968W.

(2) When the temperature of the rice cooker reaches 103℃, S1 and S2 are closed and disconnected, and R1 and R2 are connected in series, as shown in Figure 2.

Then the electric power:

P2=

U2

R1+R2

=

(220V)2

50Ω+1886Ω

=25W.

Answer: (1) The simplified circuit diagram for heating is shown in Fig. 1, and the electric power consumed by the rice cooker is 968W;

(2) The simplified circuit diagram is shown in Figure 2, at this time the electric power consumed by the rice cooker is 25W.