In the figure R1726 ohm R2218 ohm and the ideal battery has

In the figure R_1=7.26 ohm, R_2=21.8 ohm, and the ideal battery has emf epsilon=13.4 V. (a) What is the magnitude of current i_1? (b) How much energy is dissipated by all four resistors in 0.670 min?

Solution

all three R₂\'s in parallel => Req =R₂/3 =21.8/3 =7.267 ohm

current through R₁ is I =13.4 /(7.267+7.26) =0.922 A

current i₁ =0.922/3 =0.3073A

b) Power dissipated through all resistors P= I^2*(R₁+R₂/3) =0.922^2*( 7.267+7.26) =12.35 W

Energy dissipated through all resistors E=P*t =12.35*0.67*60=496.47J