Question

Two equal resistances when connected in series to a battery, consume electric power of 60 W. If these resistances are now connected in parallel combination to the same battery, the electric power consumed will be.
(A) 60 W (B) 240 W
(C) 120 W (D) 30 W

Answer 1

Answer:

In series condition, equivalent resistance is 2R

thus power consumed is 60W= ε ^2÷ 2R ln

parallel condition, equivalent resistance is R/</span><span>2 thus new power is

P' ε^2 ÷ (R/2 )

or P' = 4p = 240 W