Get premium membership and access questions with answers, video lessons as well as revision papers.

A house has five rooms each with a 60 W, 240 V bulb. If the bulbs are switched on from 7.00 pm to 10.30 pm,...

      

A house has five rooms each with a 60 W, 240 V bulb. If the bulbs are switched on from 7.00 pm to 10.30 pm, calculate the;
(a) Power consumed per day in kWh
(b) Cost per week for lighting those rooms if it costs 90 cents per unit.

  

Answers


Mutiso
(a) Power consumed by 5 bulbs = 60 × 5 = 300 W = 0.3 kWh. Time = 10.30 – 7.00 = 3 ½ hrs.
Therefore for the time duration = 0.3 × 3 ½ = 1.05 kWh.
(b) Power consumed in 7 days = 1.05 × 7 = 7.35 kWh. Cost = 7.35 × 0.9 = Ksh 6.62
Mutiso answered the question on October 16, 2018 at 18:18


Next: An electric heater is made of a wire of resistance 100 ${\Omega}$ connected to a 240 V mains supply. Determine the; (a) Power rating of...
Previous: Illustrate domestic wiring system with aid of a diagram

View More Physics Questions and Answers | Return to Questions Index


Learn High School English on YouTube

Related Questions