{"id":114,"date":"2014-10-19T08:25:56","date_gmt":"2014-10-19T08:25:56","guid":{"rendered":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsecphysu2hwrk\/?page_id=114"},"modified":"2019-03-01T09:32:55","modified_gmt":"2019-03-01T09:32:55","slug":"electricity-energy-exercise-9","status":"publish","type":"page","link":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsecphysu2hwrk\/electricity-energy-exercise-9\/","title":{"rendered":"Electricity & Energy Exercise 9"},"content":{"rendered":"

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1. Use the equations P = IV and V = IR in order to derive the equation, P = I2 R.<\/p>\n

2. Copy and complete this table:
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3. What is the power rating of a lamp that has a resistance of 5 \u2126 and a current of 1.2 A flowing through it?
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\n4. What is the current flowing through a 50 \u2126 heating element in a toaster if it has a power rating of 800 W?<\/p>\n

5. What is the resistance of a 1200 W electric convection heater that has a current of 5.0 A flowing through it.<\/p>\n

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6. Combine the equations P = IV and I = V \/ R to derive the equation P = V2 \/ R.<\/p>\n

7. Copy and complete this table:<\/p>\n

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8. What is the power rating of a mains television that has a resistance of 529 \u2126?<\/p>\n

\"\"<\/a>9. What is the voltage across a portable electric shaver that has a resistance of 2.45 \u2126 and a power rating of 20 W?<\/p>\n

10. What is the resistance of an 800 W mains powered coffee machine?<\/p>\n

11. A 130 W tropical fish aquarium is connected to the mains.<\/p>\n

(a) What is the resistance of the aquarium?<\/p>\n

(b) What is the current flowing through the aquarium?<\/p>\n

(c) How much energy is used up by the aquarium in 24 hours?<\/p>\n

12. A hairdryer has three heat settings: cold, warm and hot. The hairdryer is made up of two 300 \u2126 resistors and a 50 \u2126 motor that are connected in parallel with the mains supply, as shown.<\/p>\n

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(a) What is the energy change that occurs when current flows through a resistor?<\/p>\n

(b) Which switches are closed when the hairdryer is blowing out warm air?<\/p>\n

(c) How much current is drawn from the mains when the hairdryer is blowing out cold air?<\/p>\n

(d) What is the power rating of the hairdryer when it is blowing out cold air?<\/p>\n

(e) What is the total resistance of the hairdryer when it is blowing out hot air?<\/p>\n

(f) What is the power rating of the hairdryer when it is blowing out hot air?<\/p>\n

(g) How much electrical energy will the hairdryer use if it blows cold air for 1 minute and hot air for 8 minutes?<\/p>\n

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              1. Use the equations P = IV and V = IR in order to derive the equation, P = I2 R. 2. Copy and complete this table:             3. What is the power rating of a lamp that has a resistance of 5 … Continue reading Electricity & Energy Exercise 9<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":2454,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"open","ping_status":"open","template":"","meta":{"footnotes":""},"class_list":["post-114","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsecphysu2hwrk\/wp-json\/wp\/v2\/pages\/114","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsecphysu2hwrk\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsecphysu2hwrk\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsecphysu2hwrk\/wp-json\/wp\/v2\/users\/2454"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsecphysu2hwrk\/wp-json\/wp\/v2\/comments?post=114"}],"version-history":[{"count":10,"href":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsecphysu2hwrk\/wp-json\/wp\/v2\/pages\/114\/revisions"}],"predecessor-version":[{"id":206,"href":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsecphysu2hwrk\/wp-json\/wp\/v2\/pages\/114\/revisions\/206"}],"wp:attachment":[{"href":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsecphysu2hwrk\/wp-json\/wp\/v2\/media?parent=114"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}