A) 1/2
B) 2
C) 1/4
D) 4
Correct Answer: A
Solution :
Key Idea Power is inversely proportional to resistance provided potential difference remains constant. The rate of dissipation of electric energy is called electric power W = Vit The electric power dissipated will be is given by \[P=\frac{W}{t}=\frac{Vit}{t}=Vi\] \[=\frac{{{V}^{2}}}{R}\] ? (i) When resistance is doubled, then let electric power is P. \[\therefore \] \[p=\frac{{{V}^{2}}}{2R}\] ? (ii) From Eqs. (i) and (ii), we get \[p=\frac{1}{2}p\] So, power becomes \[\frac{1}{2}\] of initial value.
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