PHYSICS

JAMB 2001 - Question 28

Physics 2001 JAMB Past Questions - Question 28: the cost of running five 60 w lamps and four 100 w lamps for 20 hours if electrical energy costs N10.00per kwh is

Choose the correct answers from the options given.
the cost of running five 60 w lamps and four 100 w lamps for 20 hours if electrical energy costs N10.00per kwh is
A:
B:
C:
D:
Examkits App

Examkit's JAMB CBT App

Practice JAMB offline with our Online, PC and Mobile App

  • ✅ 25+ years of past questions (2000 to 2025)
  • ✅ Video solutions and explanation to questions
  • ✅ E-library
  • ✅ Study by topic
  • ✅ And more.

Correct Answer

D

Explanation

Total power =(5*60) +(4*100) =700WEnergy kwhr =power *time =700*10-3*20=14kwhr ;1 kwhr cost N1014kwhr will cost 10*10=N140To calculate the cost of running the five 60-watt lamps and four 100-watt lamps for 20 hours at a rate of N10.00 per kilowatt-hour (kWh), you can follow these steps:

Step 1: Calculate the total power consumption in kilowatts (kW):
For the five 60-watt lamps:
5 lamps * 60 watts per lamp = 300 watts = 0.3 kW

For the four 100-watt lamps:
4 lamps * 100 watts per lamp = 400 watts = 0.4 kW

Now, calculate the total power consumption:
Total power consumption = 0.3 kW (for the 60-watt lamps) + 0.4 kW (for the 100-watt lamps) = 0.7 kW

Step 2: Calculate the total energy consumption in kilowatt-hours (kWh):
Energy consumption (kWh) = Power (kW) × Time (hours)
Energy consumption = 0.7 kW × 20 hours = 14 kWh

Step 3: Calculate the cost:
Cost = Energy consumption (kWh) × Cost per kWh
Cost = 14 kWh × N10.00 per kWh = N140.00

So, the cost of running the five 60-watt lamps and four 100-watt lamps for 20 hours at a rate of N10.00 per kWh is N140.00.

Frequently Asked Questions

Examkits is a JAMB CBT practice platform that provides over 20 years of past questions, Post UTME questions, and detailed video solutions to help students prepare for their exams.

You can practice JAMB past questions online, on Android, or on a desktop using the Examkits app. Just register on our website and choose your preferred device.

Yes. Our Android and Windows versions support offline usage. Once downloaded and activated, no internet is required to use most of the features.

Yes, Examkits provides detailed video explanations for all JAMB past questions from 2000 to 2024, helping students understand how to solve each problem.

Examkits offers free practice for some subjects. However, full access requires a one-time affordable activation fee for each version of the app.