In astronomical observations, signals observed from the distant stars are generally weak. If the photon detector receives a total of $$3.15\times 10^{-18}J$$ from the radiations of 600 nm, calculate the number of photons received by the detector.

Asked by Abhisek | 1 year ago |  67

##### Solution :-

From the expression of energy of one photon (E),

$$E=\dfrac{hc}{\lambda }$$

Where,

λ denotes the wavelength of the radiation

h is Planck’s constant

c denotes the velocity of the radiation

Substituting these values in the expression for E:

$$E=\dfrac{(6.626\times 10^{-34}Js)(3\times 10^{8}ms^{-1})}{(600\times 10^{-9})}$$

$$=3.313\times 10^{-19}\, J$$

Energy held by one photon

=$$3.313\times 10^{-19}\, J$$

No. photons received with $$3.15\times 10^{-18}J\;energy$$

$$=\dfrac{3.15\times 10^{-18}J}{3.313\times 10^{-19}J }\\ \\$$

$$=9.5\\ \\ \approx 10$$

Answered by Pragya Singh | 1 year ago

### Related Questions

#### How many sub-shells are associated with n = 4?

(a) How many sub-shells are associated with n = 4?

(b) How many electrons will be present in the sub-shells having ms value of $$- \dfrac{1}{2}$$ for n = 4?

#### Indicate the number of unpaired electrons in:

Indicate the number of unpaired electrons in:

(a) P

(b) Si

(c) Cr

(d) Fe

(e) Kr

#### The unpaired electrons in Al and Si are present in 3p orbital.

The unpaired electrons in Al and Si are present in 3p orbital. Which electrons will experience more effective nuclear charge from the nucleus?

#### Among the following pairs of orbitals which orbital will experience the larger effective nuclear charge?

Among the following pairs of orbitals which orbital will experience the larger effective nuclear charge?

(i) 2s and 3s,

(ii) 4d and 4f,

(iii) 3d and 3p