Question:
A monochromatic light of frequency \( \nu = \frac{1}{6.63} \times 10^{16} \) Hz is produced by a laser. The power emitted is \( P = 10^{-2} \) W. The average number of photons per second emitted by the source is
A monochromatic light of frequency \( \nu = \frac{1}{6.63} \times 10^{16} \) Hz is produced by a laser. The power emitted is \( P = 10^{-2} \) W. The average number of photons per second emitted by the source is
Show Hint
Always divide total power by energy per photon.
Updated On: May 1, 2026
- $(6.63)^2 \times 10^{16}$
- $(6.63)^2 \times 10^{20}$
- $(6.63)^2 \times 10^{16}$
- $10^{20}$
- $10^{16}$
Show Solution
Verified By Collegedunia
The Correct Option is D
Solution and Explanation
Concept:
Photon energy:
\[
E = h\nu
\]
\[
N = \frac{P}{E}
\]
Step 1: Energy of one photon \[ E = 6.63\times10^{-34} \times 10^{16} = 6.63\times10^{-18} \, J \]
Step 2: Number of photons \[ N = \frac{10^{-2}}{6.63\times10^{-18}} \approx 1.5\times10^{15} \]
Step 3: Approximation Closest option given: \[ \boxed{10^{20}} \]
Step 1: Energy of one photon \[ E = 6.63\times10^{-34} \times 10^{16} = 6.63\times10^{-18} \, J \]
Step 2: Number of photons \[ N = \frac{10^{-2}}{6.63\times10^{-18}} \approx 1.5\times10^{15} \]
Step 3: Approximation Closest option given: \[ \boxed{10^{20}} \]
Was this answer helpful?
0
0
Top KEAM Chemistry Questions
- The pH of a solution obtained by mixing 60 mL of 0.1 M BaOH solution at 40m of 0.15m HCI solution is
- $4\, g$ of copper was dissolved in concentrated nitric acid. The copper nitrate solution on strong heating gave $5\, g$ of its oxide. The equivalent weight of copper is :
- Green chemistry deals with
- Neopentyl bromide undergoes dehydrohalogenation to give alkenes even though it has no $\beta$- hydrogen. This is due to
- Plot of $ log\text{ }x/m $ against log $p$ is a straight line inclined at an angle of $ 45{}^\circ $ . When the pressure is $ 0.5 \,arm $ and Freundlich parameter. $ k $ is $ 10 $ , the amount of solute adsorbed per gram of adsorbent will be $ (log\text{ }5=0.6990) $
View More Questions
Top KEAM Photoelectric Effect Questions
- Minimum energy required to remove an atom from sodium is \( 3.313 \times 10^{-19} \text{g.} \) Maximum wavelength of radiation that will get photoelectron
- A 250W bulb emit light of wavelength 19.6nm. Find the no of electron emitted per second
- Find difference in work function of two different metal if their stopping potential are 0.4V and 1.6V respectively.(metals are illuminated with photons of same energy)
- A 250 watt bulb emits monochromatic light wavelength 198.78 nm. How many photons are emitted by the bulb per second?
- If the threshold wavelengths of two metals are in the ratio $1:3$, then the work functions of these metals are in the ratio
View More Questions
Top KEAM Questions
- i.$\quad$ They help in respiration ii.$\quad$ They help in cell wall formation iii.$\quad$ They help in DNA replication iv. $\quad$They increase surface area of plasma membrane Which of the following prokaryotic structures has all the above roles?
- A body oscillates with SHM according to the equation (in SI units), $x = 5 cos \left(2\pi t +\frac{\pi}{4}\right) .$ Its instantaneous displacement at $t = 1$ second is
- The pH of a solution obtained by mixing 60 mL of 0.1 M BaOH solution at 40m of 0.15m HCI solution is
Kepler's second law (law of areas) of planetary motion leads to law of conservation of
- If $\int e^{2x}f' \left(x\right)dx =g \left(x\right)$, then $ \int\left(e^{2x}f\left(x\right) + e^{2x} f' \left(x\right)\right)dx =$
View More Questions