Question

Calculate the units of electricity consumed in the month of November from the following details. One $60$ W bulb used for $5$ hours daily. One $100$ W bulb is used for $3$ hours daily. One $1$ kW electric heater is used for 2 hours daily.

• A. $78$
• B. $14$
• C. $36$
• D. $18$

Answer 1

The correct option is A $78$

Energy$=E=Pt$ where $P=power$ and $t=time$

Total energy consumed$=E=(60W\times 5h+100W\times 3h+1000W\times 2h)\times 30$

$⟹E=(300+300+2000)\times 30Wh$

$⟹E=78000Wh=78kWh$

We know that $1unit=1kWh$

$⟹E=78units$

Answer-(A)