Three equal resistors connected across, a source of emf together dissipate 10 watt of power. What will be the power dissipated in watt if the same resistors are connected in parallel across the same source of emf

Options

A. `(10)/(3)`
B. 10
C. 30
D. 90

Answer

D

Explanation

90
Suppose each has resistance R
`therefore` Total resistance in series `R_(1) = 3 R `,
Total resistance in parallel `R_(2) = (R)/(3) `
Now P = `(V^(2))/(R)` , Where V = constant
`therefore P prop (1)/(R)`
`therefore (P_(2))/(P_(I)) = (R_(1))/(R_(2)) = (3R)/((R)/(3)) = 9 `
`therefore P_(2) = 9 xx 10 = 90 ` V