`(R_1////R_d)nt R_b`

`R_d=U^2/mathcal{P}=24(Omega)`

`R=(R_1R_d)/(R_1+R_d)+R_b=10,8(Omega)`

a)

`I=(mathcal(E))/(R+r)=36/(10,8+1,2)=3(A)`

b)

`I=I_b=3(A)`

`=> U_b=I_b.R_b=18(V)`

c)

`U=mathcal(E)-Ir=32,4(V)`

`=> U_d=U_(1d)=U-U_b=32,4-18=14,4`

`=> I_d=0,6(A)>I_(dm)=(mathcal(P))/(U_(dm))=0,5(A)`

`=>` Đèn sáng hơn bình thường.

d)

`Q=I^2Rt`

`=> Q_b=3^2.6.5.60=16200(J)`