Question

Answer 1

\(P=U'I=110\left(\dfrac{60}{220}\right)=30\)W

Chọn C

Answer 2

\(R_Đ=\dfrac{U_Đ^2}{P_Đ}=\dfrac{220^2}{60}=\dfrac{2420}{3}\Omega\)

Công suất đèn:

\(P_Đ=\dfrac{U_m^2}{R_Đ}=\dfrac{110^2}{\dfrac{2420}{3}}=15W\)

Chọn D.