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प्रश्न
What is the resistance of an appliance rated at V volt, P watt?
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उत्तर
Let I be the current drawn by the appliance.
Then Power, P = V × I or I = `"P"/"V"`
Now, Resistance R = `"V"/"I"`
Hence, R = V + `"P"/"V" = "V"^2/"P"`.
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