P |
U |
U2 |
RL |
U2 |
P |
A.加热,220Ω | B.加热,110Ω | C.保温,110Ω | D.保温,220Ω |
A.电流表的示数减小,电压表的示数增大 |
B.电源的输出功率变小 |
C.R2消耗的功率先变大后变小 |
D.滑动变阻器消耗的功率先变大后变小 |
A.4V,16J | B.8V,16J | C.4V,32J | D.8V,32J |
A.1.6W、0.8W | B.0.8W、0.4W | C.1.2W、0.8W | D.0.6W、0.4W |
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