Question

The electric field intensity produced by the radiations coming from 100W bulbs at a 3m distance is E. The electric field intensity produced by the radiations coming from 50W bulb at the same distance is
A. `E/2`
B. `2E`
C. `(E)/(sqrt(2))`
D. `sqrt(2E)`

Answer 1

Correct Answer - C
We know that `E_(0) prop sqrt(P_(av))`
`((E_(0))_(1))/((E_(0))_(2)) =sqrt(((P_(av)))/((P_(aq))_(2)))rArr (E)/(((E_(0))_(2)))=sqrt((1000)/(5))`
`(E_(0))_(2) =E //sqrt(2)`
Now according to question `p =50 w, P= 100w`
`:.` Putting these value in Eq. (i). we get
`(E)/(E) =(50)/(100) rArr (E)/(E) = 1/2 rArr E =(E)/(2)`