10th/9th (Foundation) Physics, Chemistry, Math Forum

Electricity

Electricity

by Sanyam Kapoor -
Number of replies: 1
Out of 60 W and 40 W lamps,which one has higher resistance when in use?

In this problem, which formula must be applied to get the result?
P = \(\frac{V^{2}}{R}\) OR P = \(I^{2}R\)

In reply to Sanyam Kapoor

Re: Electricity

by Srinath Murthy -

40 W has higher resistance.

Assuming supply is same => V is same, the first formula should be used. If I were constant the second formula should have been used.