Home
Class 11
CHEMISTRY
A 100 watt bulb emits monochromatic ligh...

A 100 watt bulb emits monochromatic light of wavelength 400 nm . Calculate the number of photons emitted per second by the bulb.

Text Solution

Verified by Experts

Power of the bulb = 100 watt
`-100Js^(-1)`
Energy of one photon `E=hv=hc//lamda`
`=(6.626xx10^(-34)Jsxx3xx10^(8)ms^(-1))/(400xx10^(-19)m)`
`=4.969xx10^(-19)J`
Number of photons emitted
`(100Js^(-1))/(4.969xx10^(-19))=2.012xx10^(20)s^(-1)`
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • ATOMIC STRUCTURE

    VIKRAM PUBLICATION ( ANDHRA PUBLICATION)|Exercise Important Questions|28 Videos

  • ATOMIC STRUCTURE

    VIKRAM PUBLICATION ( ANDHRA PUBLICATION)|Exercise VERY SHORT ANSWER QUESTIONS |39 Videos

  • CHEMICAL EQUILIBRIUM AND ACIDS BASES

    VIKRAM PUBLICATION ( ANDHRA PUBLICATION)|Exercise LONG ANSWER QUESTIONS |31 Videos

Similar Questions

Explore conceptually related problems

What is the wave number of a radiation of wavelength 400 nm ?

Estimating the following two numbers should be interesting. The first number will tell you why radio engineers do not need to worry much about photons! The second number tells you why our eye can never ‘count photons’, even in barely detectable light. (a) The number of photons emitted per second by a Medium wave transmitter of 10 kW power, emitting radiowaves of wavelength 500 m. (b) The number of photons entering the pupil of our eye per second corresponding to the minimum intensity of white light that we humans can perceive (~10^(-10) W m^(-2)) . Take the area of the pupil to be about 0.4 cm2 , and the average frequency of white light to be about 6 xx 10^(14) Hz

Knowledge Check

  • Photons of wavelength 660 nm are emitted from a 60 watt lamp. What is the number of photons emitted per second ?

    A
    `2xx10^(16)`
    B
    `2xx10^(18)`
    C
    `2xx10^(20)`
    D
    `2xx10^(22)`

  • A 1000W transmitter works at a frequency 880 kHz. The number of photons emitted per second is

    A
    `1.7xx10^(28)`
    B
    `1.7xx10^(30)`
    C
    `1.7xx10^(23)`
    D
    `17xx10^(25)`

  • Two sources A and B have same power. The wavelength of radiation of A is lamda_(a) , and that of B is lamda_(b) . The number of photons emitted per second by A and B are n_(a) & n_(b) respectively, then:

    A
    `lamda_(a)gtlamda_(b)`
    B
    if `lamda_(a)gtlamda_(b),n_(a)ltn_(b)`
    C
    if `lamda_(a)ltlamda_(b),n_(a)ltn_(b)`
    D
    if `lamda_(a)gtlamda_(b),n_(a)=n_(b)`

    • Similar Questions

    Explore conceptually related problems

    The wavelength of a blue light is 4800 Å. Calculate the frequency and wave number of this light.

    The wavelength of a blue light is 4800Å . Calculate the frequency and wave number of this light.

    The wavelength of a blue light is 4800Å . Calculate the frequency and wave number of this light.

    A bulb emits light of wavelength 4500Å . The bulb is rated as 150 watt and 8% ofthe energy is emitted as light. How many photons are emitted per sec?

    A 100W-220V bulb is connected to 110 V source. Calculate thepower consumed by the bulb.

    Home
    Profile