{"id":2903,"date":"2018-05-30T19:28:06","date_gmt":"2018-05-30T11:28:06","guid":{"rendered":"https:\/\/gurumuda.net\/physics\/?p=2903"},"modified":"2023-08-06T14:26:35","modified_gmt":"2023-08-06T14:26:35","slug":"calculation-of-the-electrical-energy-usage-by-electrical-tool-problems-and-solutions","status":"publish","type":"post","link":"https:\/\/gurumuda.net\/physics\/calculation-of-the-electrical-energy-usage-by-electrical-tool-problems-and-solutions.htm","title":{"rendered":"Calculation of the electrical energy usage by electrical tool \u2013 problems and solutions","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

Calculation of the electrical energy usage by electrical tool \u2013 problems and solutions<\/p>\n

1. <\/span><\/span>In a house, there are 5 lamps 25 Watt used 14 hours per day, a 200 Watt refrigerator used 24 hours per day, and a 125 Watt water pump used 8 hours per day. How much electrical energy<\/a> used for a month (30 days)?<\/span><\/span><\/span><\/p>\n

Known :<\/u><\/span><\/span><\/p>\n

Power of lamp = 5(25) = 125 Watt and time of use = 14 hours x 30 = 420 hours<\/span><\/span><\/p>\n

Power of <\/span><\/span>refrigerator <\/span><\/span><\/span>= 200 Watt and time of use = 24 hours x 30 = 720 hours<\/span><\/span><\/p>\n

Power of water pump = 125 Watt and time of use = 8 hours x 30 = 240 hours<\/span><\/span><\/p>\n

Wanted :<\/u><\/span><\/span> E<\/span><\/span>lectrical energy used for a month<\/span><\/span><\/span><\/p>\n

Solution :<\/u><\/span><\/span><\/p>\n

Electric energy = electric power<\/a> x time interval<\/span><\/span><\/p>\n

Energy (lamp) = (125 Watt)(420 hours) = 52,500 Watt jam = 52,5 kilo Watt hours<\/span><\/span><\/p>\n

Energy (refrigerator) = (200 Watt)(720 hours) = 144,000 Watt jam = 144 kilo Watt hours<\/span><\/span><\/p>\n

Energy (water pump) = (125 Watt)(240 hours) = 30,000 Watt jam = 30 kilo Watt hours<\/span><\/span><\/p>\n

Electrical energy used for a month <\/span><\/span><\/span>= 52,5 + 144 + 30 = 226,5 kilo Watt hour = 226,5 kilo Watt hour = <\/span><\/span>226,5 kWh.<\/span><\/span><\/p>\n

<\/p>\n

2. <\/span><\/span>A house using electrical tools as listed in the following table.<\/span><\/span><\/span><\/p>\n

\"Calculation<\/p>\n

How much electrical energy is used for 1 month (30 days)?<\/span><\/span><\/span><\/p>\n

Known :<\/u><\/span><\/span><\/p>\n

Power of lamp = 4 x 10 Watt = 40 Watt and time of use = 10 hours<\/span><\/span> x 30 = 300 hours<\/span><\/span><\/p>\n

Power of TV = 1 x 100 Watt = 100 Watt and time of use = 10 hours x 30 = 300 hours<\/span><\/span><\/p>\n

Power of iron = 1 x 300 Watt = 300 Watt and time of use = 2 hours x 30 = 60 hours<\/span><\/span><\/p>\n

Wanted :<\/u><\/span><\/span> E<\/span><\/span>lectrical energy is used for 1 month<\/span><\/span><\/span><\/p>\n

Solution :<\/u><\/span><\/span><\/p>\n

Electric energy = electric power x time<\/span><\/span><\/p>\n

Energy used by lamp = (40 Watt)(300 hours) = 12,000 Watt hours = 12 kilo Watt hours = 12 kWh <\/span><\/span><\/p>\n

Energy used by TV = (100 Watt)(300 hours) = 30,000 Watt hours = 30 kilo Watt hours = 30 kWh<\/span><\/span><\/p>\n

Energy used by iron = (300 Watt)(60 hours) = 18,000 Watt hours = 18 kilo Watt hours = 18 kWh<\/span><\/span><\/p>\n

Total energy = 12 kWh + 30 kWh + 18 kWh = 60 kWh.<\/span><\/span><\/p>\n

<\/p>\n

3.<\/span><\/span><\/p>\n

\"Calculation<\/p>\n

The electrical energy used by the above three electrical tools is…<\/span><\/span><\/span><\/p>\n

A. 158,400 Joule<\/span><\/span><\/p>\n

B. 950,400 Joule<\/span><\/span><\/p>\n

C. 5,860,800 Joule<\/span><\/span><\/p>\n

D. 9,504,000 Joule<\/span><\/span><\/p>\n

Solution<\/span><\/span><\/p>\n

Electric power of TV :<\/span><\/span><\/p>\n

P = V I = (220 Volt)(0.3 Ampere) = 66 Volt Ampere = 66 Watt = 66 Joule\/second<\/span><\/span><\/p>\n

Electric power of computer :<\/span><\/span><\/p>\n

P = V I = (220 Volt)(0.4 Ampere) = 88 Volt Ampere = 88 Watt = 88 Joule\/second<\/span><\/span><\/p>\n

Electric power of water pump :<\/span><\/span><\/p>\n

P = V I = (220 Volt)(0.5 Ampere) = 110 Volt Ampere = 110 Watt = 110 Joule\/second<\/span><\/span><\/p>\n

Time interval :<\/span><\/span><\/p>\n

10 hours = 10 x 3600 seconds = 36,000 seconds<\/span><\/span><\/p>\n

6 hours = 6 x 3600 seconds = 21600 seconds<\/span><\/span><\/p>\n

4 hours = 4 x 3600 seconds = 14400 seconds<\/span><\/span><\/p>\n

Electric energy = electric power x time<\/b><\/span><\/span><\/p>\n

Electric energy used by TV = <\/span><\/span>66 Joule\/second<\/span><\/span> x <\/span><\/span>36,000 seconds <\/span><\/span>= 2,376,000 Joule<\/span><\/span><\/p>\n

Electric energy used by computer = 88 Joule\/second x <\/span><\/span>21,600 seconds <\/span><\/span>= 1,900,800 Joule<\/span><\/span><\/p>\n

Electric energy used by water pump = <\/span><\/span>110 Joule\/seconds <\/span><\/span>x <\/span><\/span>14,400 seconds <\/span><\/span>= 1,584,000 Joule<\/span><\/span><\/p>\n

Total electric energy :<\/span><\/span><\/p>\n

2,376,000 Joule + 1,900,800 Joule + 1,584,000 Joule = 5,860,800 Joule<\/span><\/span><\/p>\n

<\/p>\n

4. <\/span><\/span>A family uses electrical energy for a month (30 days) for tools as in the following table!<\/span><\/span><\/span><\/p>\n

\"Calculation<\/p>\n

Electric power of washing machine, TV and AC are…<\/span><\/span><\/p>\n

\"Calculation<\/p>\n

Solution :<\/span><\/span><\/p>\n

Electric energy of washing machine = 12 kWh = 12,000 Watt hour, time of use = 2 hours x 30 = 60 hours<\/span><\/span><\/p>\n

Electric energy of TV = 19.2 kWh = 19,200 Watt hour, time of use = 8 hours x 30 = 240 hours<\/span><\/span><\/p>\n

Electric energy of AC = 72 kWh = 72,000 Watt hour, time of use = 6 hours x 30 = 180 hours<\/span><\/span><\/p>\n

Electric power = electric energy \/ time<\/span><\/span><\/p>\n

Electric power of washing machine = 12,000 Watt hour \/ 60 hours = 200 Watt <\/span><\/span><\/p>\n

Electric power TV = 19,200 Watt hour \/ 240 hours = 80 Watt <\/span><\/span><\/p>\n

Electric power AC = 72,000 Watt hour \/ 180 hours = 400 Watt<\/span><\/span><\/p>\n","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"

Calculation of the electrical energy usage by electrical tool \u2013 problems and solutions 1. In a house, there are 5 lamps 25 Watt used 14 hours per day, a 200 Watt refrigerator used 24 hours per day, and a 125 Watt water pump used 8 hours per day. How much electrical energy used for a … Read more<\/a><\/p>\n","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_seopress_titles_title":"","_seopress_titles_desc":"","_seopress_robots_index":"","_seopress_robots_follow":"","_seopress_robots_imageindex":"","_seopress_robots_snippet":"","_seopress_robots_primary_cat":"","_seopress_robots_breadcrumbs":"","_seopress_robots_freeze_modified_date":"","_seopress_robots_custom_modified_date":"","_seopress_robots_canonical":"","_seopress_social_fb_title":"","_seopress_social_fb_desc":"","_seopress_social_fb_img":"","_seopress_social_fb_img_attachment_id":0,"_seopress_social_fb_img_width":0,"_seopress_social_fb_img_height":0,"_seopress_social_twitter_title":"","_seopress_social_twitter_desc":"","_seopress_social_twitter_img":"","_seopress_social_twitter_img_attachment_id":0,"_seopress_social_twitter_img_width":0,"_seopress_social_twitter_img_height":0,"_seopress_redirections_value":"","_seopress_redirections_enabled":"","_seopress_redirections_enabled_regex":"","_seopress_redirections_logged_status":"","_seopress_redirections_param":"","_seopress_redirections_type":0,"_seopress_analysis_target_kw":"Calculation of the electrical energy usage by electrical tool \u2013 problems and solutions","_seopress_news_disabled":"","_seopress_video_disabled":"","_seopress_video":[],"_seopress_pro_schemas_manual":[],"_seopress_pro_rich_snippets_disable_all":"","_seopress_pro_rich_snippets_disable":[],"_seopress_pro_schemas":[],"footnotes":""},"categories":[3],"tags":[],"class_list":["post-2903","post","type-post","status-publish","format-standard","hentry","category-solved-problems-in-basic-physics"],"gt_translate_keys":[{"key":"link","format":"url"}],"_links":{"self":[{"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/posts\/2903","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/comments?post=2903"}],"version-history":[{"count":1,"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/posts\/2903\/revisions"}],"predecessor-version":[{"id":8538,"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/posts\/2903\/revisions\/8538"}],"wp:attachment":[{"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/media?parent=2903"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/categories?post=2903"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/tags?post=2903"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}