Question

Two electric appliances of power rating `W_(1) and W_(2)` t 240 V are connected in parallel with a source of alternating voltage`e=240sqrt(2)sinomegat`. The resultant power consumed is
A. `W_(1)+W_(2)`
B. `W_(1)-W_(2)`
C. `(1)/(W_(1))+(1)/(W_(2))`
D. `(W_(1)W_(2))/(W_(1)+W_(2))`

Answer 1

Correct Answer - A
In parallel combination,
`(1)/(R_(P))=(1)/(R_(1))+(1)/(R_(2))`
`therefore (1)/(V^(2)//W_(P))=(1)/(V^(2)//W_(1))+(1)/(V^(2)//W_(2))`
`therefore W_(P)=W_(1)+W_(2)`