A heater works at 800 W for the first 10 minutes and at 1.2 kW for the next 20 minutes

PHYSICS · Single correct · CBSE · Physics · Current Electricity · Current Electricity

Problem

A heater works at 800 W for the first 10 minutes and at 1.2 kW for the next 20 minutes. If only 85 % of the electrical energy is converted into heat, the total heat produced in the 30 minutes is closest to (a) 2.26×103 kJ2.26\times10^{3}\,\text{kJ} (b) 1.53×103 kJ1.53\times10^{3}\,\text{kJ} (c) 1.63×103 kJ1.63\times10^{3}\,\text{kJ} (d) 1.92×103 kJ1.92\times10^{3}\,\text{kJ}

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