(1)因为R1和R2并联在电路中,所以U2=U1=I1R1=0.2AX20Ω=4V I2=U2/R2=4V/10Ω=0.4A 所以I=I1+I2=0.2A+0.4A=0.6A
(2)P2=U2I2=4VX0.4A=1.6W
(3)Q2=P2t=1.6WX60s=96J
(1)因为R1和R2并联在电路中,所以U2=U1=I1R1=0.2AX20Ω=4V I2=U2/R2=4V/10Ω=0.4A 所以I=I1+I2=0.2A+0.4A=0.6A
(2)P2=U2I2=4VX0.4A=1.6W
(3)Q2=P2t=1.6WX60s=96J