How to Determine the Brightness of Bulbs in a New Configuration?

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To determine the brightness of bulbs in a new configuration, the relationship between power and voltage is crucial, as brightness is proportional to power. The equations P = V²/R and P = I²R can yield different results depending on the approach used. In this case, bulb "g" receives 2V, making it brighter than normal, while bulb "h" remains at normal brightness with voltage V. Clarification is sought on whether it is acceptable to rely solely on one formula for accurate results. Posting detailed calculations is recommended for verification of the findings.
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Homework Statement



See attachment
The question asks to calculate the brightness of the bulbs(g and h) in this new configuration.


Homework Equations



Since brightness \propto Power

P= V^{2}/R
P= I^{2}R
E.M.F of One cell : V

The Attempt at a Solution



I used the equation P = V^(2)/R

Since the Voltage across "g" will be 2V and its Resistance is exactly the same as in the reference Attachment, "g" will be brighter than normal.
Similarly, since the Voltage across "h" is going to be V, "h" must be of normal brightness.

I am not sure if my answers make sense since if we apply the 2nd formula : P=R*I^2
we would get a different set of results .

Is it O.K to just rely on one of the two formulas and deduce the final answer based on say P=V^(2)/R ? Would the answers be authentic ?
 

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hms.tech said:
I am not sure if my answers make sense since if we apply the 2nd formula : P=R*I^2
we would get a different set of results .
Not if you do it correctly. Pls post your working.
 

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