Question

The three light bulbs in the circuit below are identical, and the battery has zero internal resistance, When switch S is closed to cause buil 1 to light, which of the ther two bulbs increase (s) in brightness ?

A. Neither bulb
B. Bulb 2 only
C. Bulb 3 only
D. Both bulbs

Answer 1

Correct Answer - C

Old situation
`P_(2)=((epsi)/(2))^(2)1/R=(epsi^(2))/(4R)`
`P_(3)=((epsi)/(2))^(2)1/R=(epsi^(2))/(4R)`

New situation
`P_(2)` wil be lasser than `(epsi^(2))/(4R)`
`P_(3)` will be more than `(epsi^(2))/(4R)`