(1)t=5min=300s;由Q=I2Rt=U2Rt变形可得:
R=U2Qt=(3V)290J×300s=30Ω;(2)由欧姆定律得:I=UR=3V30Ω=0.1A;
(3)当电流变为原来2倍后,即I=0.2A,产生热量为:Q=I2Rt=(0.2A)2×30Ω×300s=360J;故答案为:(1)30;(2)0.1;(3)360.
来源:搜全贸(1)t=5min=300s;由Q=I2Rt=U2Rt变形可得:
R=U2Qt=(3V)290J×300s=30Ω;(2)由欧姆定律得:I=UR=3V30Ω=0.1A;
(3)当电流变为原来2倍后,即I=0.2A,产生热量为:Q=I2Rt=(0.2A)2×30Ω×300s=360J;故答案为:(1)30;(2)0.1;(3)360.
来源:搜全贸