Answer: The current is 9.1a. ..
(2) The heat absorbed by water Q = cm (t-t0) = cρ V (t-t0) = 4.2×103j/kg? ℃× 1× 103kg/m3×40× 10-3 m3×(70℃-20℃)= 8.4× 106j。
So t = WP = 8.4×106j2000w = 4200s.
Answer: It takes 4200 s from turning on the power to turning off the indicator light.