JEE MAIN - Physics (2024 - 30th January Evening Shift - No. 8)
When a potential difference $$V$$ is applied across a wire of resistance $$R$$, it dissipates energy at a rate $$W$$. If the wire is cut into two halves and these halves are connected mutually parallel across the same supply, the energy dissipation rate will become:
1/2W
4W
1/4W
2W
Explanation
$$\begin{aligned} & \frac{\mathrm{v}^2}{\mathrm{R}}=\mathrm{W} \qquad \text{.... (i)}\\ & \frac{\mathrm{v}^2}{\frac{1}{2}\left(\frac{\mathrm{R}}{2}\right)}=\mathrm{W}^{\prime} \quad \text{.... (ii)} \end{aligned}$$
From (i) & (ii), we get
$$W^{\prime}=4 W$$
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