Question

A copper kettle of mass 1 kg contains 0.9 kg of water at 15°C. It takes 12 minutes to raise the temperature to 95°C. If the electric energy is supplied at 220V, calculate the electric current, assuming 10% of heat is wasted. Given specific heat of copper = 420 J kg-K-1 and specific heat of water = 4200 J kg-1 K-1.

A. 5.8 A
B. 6.0 A
C. 6.2 A
D. 6.5 A

Answer 1

The question involves calculating the necessary electric current to heat water using an electric kettle, factoring in the specific heat of water and copper, and the efficiency of the heating process.

Step-by-step explanation:

The student is tasked with calculating the electric current required to heat water in an electric kettle from 15°C to 95°C in 12 minutes, given a power supply voltage of 220V and assuming 10% of the heat is wasted. The student must account for the specific heat capacities of copper and water to calculate the total heat energy required and then apply the electrical power formula to derive the current.