Two litres of water kept in a container at \( 27^\circ \text{C} \) is heated with a coil of 1 kW. The lid of the container is open and energy dissipates at the rate of 160 J/s. If the specific heat of water is 4.2 kJ/kg, then the time taken by coil to raise the temperature of water from \( 27^\circ \text{C} \) to \( 77^\circ \text{C} \) is: