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Question
An electric bulb is rated at 220 V, 100 W.
- What is its resistance?
- What safe current can be passed through it?
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Solution
- Given,
Power P = 100 W
Voltage V = 220 V
As power, P = `"V"^2/"R"`
R = `(220)^2/100`
= 484 Ω - The safe limit of current that can pass through it
I = `"P"/"V"`
I = `100/220`
= 0.45 A
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