Question

Answer 1

\(Q=I^2.R.t=2,5^{2.80}.1=500j\)

\(Q_i=m.c.\text{Δ}t=1,5.4200.75=472500j\)

\(Q_{tp}=I^2.R.t=2,5^2.80.1200=600000j\)

\(H=\dfrac{Q_i}{Q_{tp}}.100\%=\dfrac{472500}{600000}.100=78,75\%\)

\(\text{P }=I^2.R=2,5^2.80=500W\)

\(A=\text{P }.t=0,5.90=45k\text{w}h\)

Tiền điện:

\(45.700=31500\) đồng

 

 

Answer 2

31500 đồng