A circular conducting coil of radius 1m is being heated by the...

$ϕ = \overset{\to}{B} \cdot \overset{\to}{S}$

$ϕ = \dfrac{4}{\pi} \times {10}^{- 3}\left(1 - \dfrac{t}{100}\right) \cdot \pi{R}^{2}$

$ϕ = 4 \times {10}^{- 3} \times {\left(1\right)}^{2}\left(1 - \dfrac{t}{100}\right)$

$ε = \dfrac{- \text{d}ϕ}{\text{d}t}$

$ε = \dfrac{- \text{d}}{\text{d}t}\left(4 \times {10}^{- 3}\left(1 - \dfrac{t}{100}\right)\right)$

$ε = 4 \times {10}^{- 3}\left(\dfrac{1}{100}\right) = 4 \times {10}^{- 5}V$

When $B = 0$

$1 - \dfrac{t}{100} = 0$

$t = 100sec$

Heat $= \dfrac{{ε}^{2}}{R}t$

Heat $= \dfrac{{\left(4 \times {10}^{- 5}\right)}^{2}}{2 \times {10}^{- 6}} \times 100J$

Heat $= \dfrac{16 \times {10}^{- 10} \times 100}{2 \times {10}^{- 6}}J$

Heat $= 0 . 08J$

Heat $= 80mJ$