Question 294: Current Electricity

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 :

Accepted Answer

In series condition, equivalent resistance is 2R
thus power consumed is 60W = $${{{\varepsilon ^2}} \over {2R}}$$
In parallel condition, equivalent resistance is R/2 thus new power is
P' = $${{{\varepsilon ^2}} \over {\left( {R/2} \right)}}$$
or   P' = 4P = 240W

Answer

240 W

Answer

60 W

Answer

30 W

Answer

120 W

Current Electricity

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 :

Choose the correct answer: