Finding the Cost to Power Light Bulbs (Example Problem) and Defining KiloWatt Hour

The video tutorial covers the concept of energy savings using energy-efficient light bulbs. It explains the calculation of power and energy usage, focusing on the difference between 15-watt and 65-watt bulbs. The tutorial includes a detailed analysis of cost savings over time and introduces the concept of kilowatt-hours (kWh), explaining its conversion to joules. The lesson also covers the calculation of electrical resistance using Ohm's Law and discusses the importance of understanding energy consumption in household circuits.

What is the primary claim made about the energy-efficient light bulbs?

• They last longer than regular bulbs.

• They are brighter than regular bulbs.

• They are cheaper to purchase.

• They save $108 in energy costs per package.

How is the change in power calculated when replacing a 65 Watt bulb with a 15 Watt bulb?

• By dividing the initial power by the final power.

• By adding the two power values.

• By subtracting the initial power from the final power.

• By multiplying the two power values.

What is the resistance of a 15 Watt light bulb connected to a 120-volt circuit?

• 15 ohms

• 960 ohms

• 120 ohms

• 240 ohms

How much money is saved per year by using the energy-efficient bulbs for 3 hours a day?

• $12.00

• $108.00

• $19.72

• $50.00

For how many years must the bulbs last to achieve the claimed savings of $108?

• 3 years

• 5.5 years

• 10 years

• 2 years

What is the equivalent of 1 kWh in joules?

• 3,600,000 joules

• 1,000,000 joules

• 3,600 joules

• 1,000 joules

Why is it important to understand the conversion of kWh to joules?

• Because it is a unit of temperature.

• Because it is used to measure time.

• Because it is a common unit of energy measurement.

• Because it helps in calculating power.