A single phase energy meter has a constant of 1200 revolution/kWh. When a load of 200 W is connected, the disc rotates at 4.2 revolutions per min. If the load is on for 10 hours, the meter records an excess of
(a) 0.1 kWh (b) 0.2 kWh (c) 1.0 kWh (d) 2.0 kWh
(a) 0.1 kWh (b) 0.2 kWh (c) 1.0 kWh (d) 2.0 kWh