Question

Let’s find out the heat developed in 3 minutes by a device of resistance 920 Ω working under 230 v​

Answer 1

Answer:

$\sf Given \begin {cases} & \sf { Current \: = \: 20\: A } \\ & \sf{ Resistance = \: 920 } \\ &\sf { time = \: 3 min = 180 sec } \end {cases}$

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$\sf To \: find \begin {cases} & \sf { Heat\: = \: ?? } \\ \end {cases}$

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Using Joule's equation of electrical heating :-

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$\star\;{\boxed{\sf{\pink{Heat ( H ) = Current ( I ) ^2 \times Resistance ( R ) \times Time ( T) }}}}$

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$:\implies\sf H = 2 \times 2 \times 920 \times 180$

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$:\implies\sf H = 4 \times 920 \times 180$

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$:\implies \sf H = 3680 \times 180$

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$:\implies \sf H = 662400 Joules$

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$:\implies{\underline{\boxed{\frak{\purple{ Heat \: = 662400\: joules\: }}}}}\;\bigstar$

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