A) 2 : 5
B) 5 : 2
C) 3 : 4
D) 4 : 3
Correct Answer: A
Solution :
Resistance of bulb \[R=\frac{{{V}^{2}}}{P}\] As V is constant hence, \[R\propto \frac{1}{P}\] or \[\frac{{{R}_{1}}}{{{R}_{2}}}=\frac{{{P}_{2}}}{{{P}_{1}}}\] Here, \[{{P}_{1}}=250\,W,{{P}_{2}}=100\,W\] \[\therefore \] \[\frac{{{R}_{1}}}{{{R}_{2}}}=\frac{100}{250}=\frac{2}{5}\]You need to login to perform this action.
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