PrepRung
Sign inSign up free

NDA 2020 GAT · General Knowledge · Current Electricity · easy

An electric heater rated 2 kW is used for 30 minutes. The electrical energy consumed is

Single correct option

An electric heater rated 2 kW is used for 30 minutes. The electrical energy consumed is
  1. A. 2 kWh
  2. B. 60 kWh
  3. C. 0.5 kWh
  4. D. 1 kWh
Show answer and solution

Answer: (D) 1 kWh

Energy = power x time = 2 kW x 0.5 h = 1 kWh, which equals 3.6 x 10^6 J. A common error is to ignore the time conversion and give 2 kWh. Since 1 kWh is one commercial unit of electricity, the heater consumes one unit.
Report a mistake

Original question written in the NDA 2020 GAT pattern and checked twice for the correct answer. Not an official question paper. How we write and check questions · Corrections policy · Report a mistake