There are two sources of light,each emitting | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(A) The power of radiation is given by $P = \frac{n h c}{t \lambda}$,where $n$ is the number of photons emitted in time $t$.Let $n'$ be the number of

Vedclass · Accepted Answer

$1:500$

Vedclass · Answer

(A) The power of radiation is given by $P = \frac{n h c}{t \lambda}$,where $n$ is the number of photons emitted in time $t$.Let $n'$ be the number of photons emitted per unit time,so $n' = \frac{n}{t}$.Thus,$P = n' \frac{h c}{\lambda}$,which implies $n' = \frac{P \lambda}{h c}$.Since $P$,$h$,and $c$ are constant for both sources,we have $n' \propto \lambda$.Therefore,the ratio of the number of photons is $\frac{n'_1}{n'_2} = \frac{\lambda_1}{\lambda_2}$.Given $\lambda_1 = 1 \, nm$ and $\lambda_2 = 500 \, nm$.Substituting the values,$\frac{n'_1}{n'_2} = \frac{1 \, nm}{500 \, nm} = \frac{1}{500}$.

There are two sources of light,each emitting with a power of $100 \, W$. One emits $X$-rays of wavelength $1 \, nm$ and the other visible light at $500 \, nm$. Find the ratio of the number of photons of $X$-rays to the photons of visible light of the given wavelength.

Similar Questions

$A$ laser produces a beam of light of frequency $5 \times 10^{14} \,Hz$ with an output power of $33 \,mW$. The average number of photons emitted by the laser per second is (Planck's constant $h = 6.6 \times 10^{-34} \,J \,s$)

$A$ sensor is exposed for time $t$ to a lamp of power $P$ placed at a distance $l$. The sensor has a circular opening that is $4d$ in diameter. Assuming all energy of the lamp is given off as light,the number of photons entering the sensor if the wavelength of light is $\lambda$ is (given $l >> d$):

The frequency of a photon with energy $100 \ eV$ is ........... $Hz$. (Given: $h = 6.62 \times 10^{-34} \ J \cdot s$,$1 \ eV = 1.6 \times 10^{-19} \ J$)

The ratio of the energy of a photon with $\lambda = 150\,nm$ to that with $\lambda = 300\,nm$ is

If the energy of a photon corresponding to a wavelength of $6000 \mathring{A}$ is $3.2 \times 10^{-19} \ J$,the photon energy for a wavelength of $4000 \mathring{A}$ will be . . . . . . .

Vedclass Test Series

Exam Paper Generator

Online Exam Module