If $R_{1}$ and $R_{2}$ are the resistances of filaments of a $400\, W$ and a $200\, W$ lamp, designed to operate on the same voltage, then
If $R_{1}$ and $R_{2}$ are the resistances of filaments of a $400\, W$ and a $200\, W$ lamp, designed to operate on the same voltage, then
- A
$R_{2}=2 R_{1}$
- B
$R_{2}=4 R_{1}$
- C
$R_{1}=2 R_{2}$
- D
$R_{1}=R_{2}$
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