A heating coil is labelled 100, W,220, V. The | vedclass

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(B) The power $P$ of a heating coil is given by $P = V^2 / R$,where $V$ is the voltage and $R$ is the resistance.Initially,$P_1 = 100\, W$ and $V = 22

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$400$

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(B) The power $P$ of a heating coil is given by $P = V^2 / R$,where $V$ is the voltage and $R$ is the resistance.Initially,$P_1 = 100\, W$ and $V = 220\, V$. Thus,$R = V^2 / P_1$.When the coil is cut into two equal halves,the resistance of each piece becomes $R' = R / 2$.When these two pieces are connected in parallel,the equivalent resistance $R_{eq}$ is given by $1 / R_{eq} = 1 / R' + 1 / R' = 2 / R' = 2 / (R / 2) = 4 / R$.Therefore,$R_{eq} = R / 4$.The new power consumed is $P_2 = V^2 / R_{eq} = V^2 / (R / 4) = 4 	imes (V^2 / R) = 4 	imes P_1$.Substituting the value,$P_2 = 4 	imes 100\, W = 400\, W$.Since $1\, W = 1\, J/s$,the energy liberated per second is $400\, J/s$.

$A$ heating coil is labelled $100\, W$,$220\, V$. The coil is cut in half and the two pieces are joined in parallel to the same source. The energy now liberated per second is .............. $J/s$.

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