InterviewSolution
Saved Bookmarks
| 1. |
A bulb emits light of ` 4500 Å `. The bulb is rated as ` 150` watt and ` 9 %` of the energy is emited as light . How many photons are emitted by the bulb per second ? |
|
Answer» We know , Energy one photon `= ( hc)/( lambda) ` ` = ( 6. 6625 xx 10 ^(-34) xx 3xx 10^8 )/( 4500 xx 10^(-10)) J = 4 . 42 xx 10^(-19) J` Energy emitted by bulb`= 15 0 xx 8/( 100 ) J //sec` Energy emitted by bulb = ` 150xx 8/( 100) J//sec` `(watt = J//sec )` `:. n xx 4.44 xx 10 10^(19) = 150 xx 8/( 100) ` ( where (n) is no. of photons ) `:. n= 27 . 2 xx 10 ^(18)`. |
|