Current Electricity Question 20
Question 20 - 2024 (30 Jan Shift 2)
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 same supply, the energy dissipation rate will become:
(1) $1 / 4 W$
(2) $1 / 2 W$
(3) $2 W$
(4) $4 W$
Show Answer
Answer: (4)
Solution:
$\frac{v^{2}}{R}=W$…(i)
$\frac{v^{2}}{\frac{1}{2}\left(\frac{R}{2}\right)}=W^{\prime}$
From (i) $ \&$ (ii),
we get $W^{\prime}=4 W$
