An electric toaster has resistance of $60 \Omega$ at room temperature $\left(27^{\circ} \mathrm{C}\right)$. The toaster is connected to a $220 \mathrm{~V}$ supply. If the current flowing through it reaches $2.75 \mathrm{~A}$, the temperature attained by toaster is around : ( if $\alpha=2 \times 10^{-4}$/$^\circ \mathrm{C}$)
Solution
<p>$$\begin{aligned}
& \mathrm{R}_{\mathrm{T}-27}=60 \Omega, R_T=\frac{220}{2.75}=80 \Omega \\
& \mathrm{R}=\mathrm{R}_0(1+\alpha \Delta \mathrm{T}) \\
& 80=60\left[1+2 \times 10^{-4}(\mathrm{~T}-27)\right] \\
& \mathrm{T} \approx 1694^{\circ} \mathrm{C}
\end{aligned}$$</p>
About this question
Subject: Physics · Chapter: Current Electricity · Topic: Ohm's Law and Resistance
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