Q1) The interior lighting of refrigerator is provided by incandescent lamps whose switches are actuated by...

Q1) The interior lighting of refrigerator is provided by incandescent lamps whose switches are actuated by the opening of the refrigerator door. Consider a refrigerator whose 50 W light bulb remains switched on continuously as a result of malfunction of the switch. If the refrigerator has a coefficient of performance of 1.25 and the cost of electricity is 9 pence per kWh, determine the increase in the energy consumption of the refrigerator and its cost per year (365 days) if the switch is not fixed. You may assume that the refrigerator is opened 30 times per day for an average of 20 seconds on each occasion.

Solutions

Expert Solution

(a) Calculating the total cost per year of the refrigerator without malfunction of the light switch :

Energy = Power x time (per year)

Power has unit as watt hence as given that the power used by the lamp is 50 W

Total time in hours per year while the refrigerator opens 30 times a day for an average of 20 seconds each occasion :

a day 30 times x av. 20 sec = [600 sec/ 60] min = 10 minutes per day

A year time utilised in hr = 10 min/day x 365 days = [3650 mins/ 60] hr = 60.833 hr/year

Energy (a) used per year = 50 x 60.633 = 3.04 kWh

Total cost (a) per year since 9 pence per KWh given = 9p x 3.04 kWh = 27.37p for units used

(b)

Calculating the total cost per year of the refrigerator with a malfunction of the light switch :

Energy = Power x time (per year)

Power has unit as watt hence as given that the power used by the lamp is 50 W

Total time in hours per year while the refrigerator opens 30 times a day for an average of 20 seconds each occasion :

a day = 1440 minutes per day

A year time utilised in hr = 1440 min/day x 365 days = [525600 mins/ 60] hr = 8760 hr/year

Energy (b) used per year = Power x time (per year) =50 W x 8760 hr = 438000 W/1000 = 438 kWh

Total cost (b) per year since 9 pence per KWh given = 9p x 438 kWh = 39.42 GBP

Hence increase in energy consumption per year = [ energy (b) - energy (a)] = (438 - 3.04) kWh= 434.9 kWh

While increase in energy consumption per year = [Cost (b) - Cost (a)] = 39.14 GBP

queen_honey_blossom answered 1 year ago

Next > < Previous

Related Solutions

Hopkins Lighting Company is a wholesale lighting company that purchases lamps and resells them to retail...

Hopkins Lighting Company is a wholesale lighting company that purchases lamps and resells them to retail customers. Hopkins is beginning operations on October 1, 2019. Hopkins Lighting Company stocks three inventory items: desk lamps, table lamps, and floor lamps. Hopkins uses a perpetual inventory system. All expenses associated with the office are Administrative Expenses and all expenses associated with the wharehouse are selling expenses. Hopkinss has hired you to assist them regarding what inventory flow method to adopt. Hopkinss not...

A computer call center is going to replace all of its incandescent lamps with more energy...

A computer call center is going to replace all of its incandescent lamps with more energy efficient fluorescent lighting fixtures. The total energy savings are estimated to be $1,875 per year, and the cost of purchasing and installing the fluorescent fixtures is $4,900. The study period is five years, and terminal values for the fixtures are negligible. What is the IRR of this investment? Express your answer in percent rounded to two decimal places. STEP BY STEP SOLUTION PLS NO...

(b) Fluorescent lamps are much more efficient than traditional incandescent bulbs. The explanation lies in the...

(b) Fluorescent lamps are much more efficient than traditional incandescent bulbs. The explanation lies in the way each produces light. When light is produced by the incandescent bulbs, electrical energy passes through a wire, heating it until glows. The wire, called a filament, typically is made of tungsten. The enclosing bulbs around the filament directs or diffuses the light. The problem is that 90% of the energy put into such a bulb is released in the form of heat while...

How does an interior designer blend lighting design into overall design?

Dave's Lighting Inc. produces lamps for the construction industry. During the year, the company incurred the...

Dave's Lighting Inc. produces lamps for the construction industry. During the year, the company incurred the following costs: Factory Rent $ 80,000 Direct labor used 425,000 Factory utilities 50,000 Direct materials purchases 600,000 Indirect materials 150,000 Indirect labor 90,000 Inventories for the year were: January 1 December 31 Direct materials $ 100,000 $ 75,000 Work in process 20,000 10,000 Finished goods 250,000 215,000 Required: Prepare a statement of Cost of Goods Sold.

t the end of 20X4, Sherpa Lighting Ltd. has a large stock of incandescent lighting fixtures that are becoming obsolete due to a new trend to low energy fluorescent and LED li...

At the end of 20X4, Sherpa Lighting Ltd. has a large stock of incandescent lighting fixtures that are becoming obsolete due to a new trend to low energy fluorescent and LED lighting fixtures. The current inventory of incandescent fixtures has a cost of $170,000. The sales manager of Sherpa estimates that the inventory can be sold through the normal course of business over the next several reporting quarters for approximately $150,000. Sales personnel are given a 10% commission on sales....

Neon Light Company of Kansas City ships lamps and lighting appliances throughout the country. Ms. Neon...

Neon Light Company of Kansas City ships lamps and lighting appliances throughout the country. Ms. Neon has determined that through the establishment of local collection centers around the country, she can speed up the collection of payments by two days. Furthermore, the cash management department of her bank has indicated to her that she can defer her payments on her accounts by one-half day without affecting suppliers. The bank has a remote disbursement center in Florida. a. If Neon Light...

Thornton Company sells lamps and other lighting fixtures. The purchasing department manager prepared the following inventory...

Thornton Company sells lamps and other lighting fixtures. The purchasing department manager prepared the following inventory purchases budget. Thornton’s policy is to maintain an ending inventory balance equal to 15 percent of the following month’s cost of goods sold. April’s budgeted cost of goods sold is $84,000 Required Complete the inventory purchases budget by filling in the missing amounts. Determine the amount of cost of goods sold the company will report on its first quarter pro forma income statement. Determine...

Rundle Company sells lamps and other lighting fixtures. The purchasing department manager prepared the following inventory...

Rundle Company sells lamps and other lighting fixtures. The purchasing department manager prepared the following inventory purchases budget. Rundle’s policy is to maintain an ending inventory balance equal to 15 percent of the following month’s cost of goods sold. April’s budgeted cost of goods sold is $83,000. Required Complete the inventory purchases budget by filling in the missing amounts. Determine the amount of cost of goods sold the company will report on its first quarter pro forma income statement. Determine...

Subjects