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An Electric Bulb is Rated at 220 V, 100 W. What is Its Resistance? What Maximum Current Can Be Passed Through It? - Physics

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Question

An electric bulb is rated at 220 V, 100 W. What is its resistance? What maximum current can be passed through it?
Numerical
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Solution

Given, P = 100 W, p.d. = 220 V

We know that,

P = `"V"^2/"R"`

P = `"V"^2/"R" = *(220)^2/100 = 484 Omega`

Also, we know that,

P=VI

I = `"P"/"V" = 100/220 = 0.45`A

Thus a fuse of rating 7A may be used with the appliance and it should be connected in the live wire before connectimg it to the appliance

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Chapter 4: Current Electricity - Exercise 4.2 ii [Page 188]

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Frank Physics - Part 2 [English] Class 10 ICSE
Chapter 4 Current Electricity
Exercise 4.2 ii | Q 19 | Page 188

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