admin

19.07.2022 - 09:28

A light-emitting diode (LED) connected to a 3.0 V power supply emits 440 nm blue light. The current in the LED is 21 mA , and the LED is 61 % efficient at converting electric power input into light po

Question:

A light-emitting diode (LED) connected to a 3.0 V power supply emits 440 nm blue light. The current in the LED is 21 mA , and the LED is 61 % efficient at converting electric power input into light power output.

How many photons per second does the LED emit?

Answers (0)

Janna April 10, 2023 в 11:14

To calculate the number of photons per second emitted by the LED, we need to use the formula: Number of photons per second = (Power of light / Energy per photon) We can find the power of light by multiplying the voltage and current: Power of light = Voltage ? Current = 3.0 V ? 21 mA = 0.063 W To find the energy per photon, we can use the formula: Energy per photon = Planck's constant ? speed of light / wavelength Planck's constant = 6.626 ? 10^-34 J s Speed of light = 3 ? 10^8 m/s Wavelength = 440 nm = 440 ? 10^-9 m Energy per photon = 6.626 ? 10^-34 J s ? 3 ? 10^8 m/s / 440 ? 10^-9 m Energy per photon = 4.51 ? 10^-19 J Now we can substitute the values into the formula for the number of photons per second: Number of photons per second = 0.063 W ? 0.61 / (4.51 ? 10^-19 J) Number of photons per second = 1.12 ? 10^18 photons/s Therefore, the LED emits 1.12 ? 10^18 photons per second.

Do you know the answer?

Leave a comment Cancel Response

Not sure about the answer?

Find the right answer to the question A light-emitting diode (LED) connected to a 3.0 V power supply emits 440 nm blue light. The current in the LED is 21 mA , and the LED is 61 % efficient at converting electric power input into light po by subject Physics, and if there is no answer or no one has given the right answer, then use the search and try to find the answer among similar questions.

Search for other answers

New questions in the category: Physics

Two fire trucks have sirens that emit waves of the same frequency. As the fire trucks approach a person, the person hears a higher frequency from truck X than from truck Y. Which of the following sta

The AM1004-T61 magnesium alloy tube AB is capped with a rigid plate E. The gap between E and end C of the 6061-T6 aluminum alloy solid circular rod CD is 0.2 mm when the temperature is at 30 degree C.

What is the world’s smallest magnet?

A thin copper plate of diameter 6 cm is charged to 8.40 nC. What is the strength of the electric field 0.1 mm above the center of the top surface plate? a. 2.47 times10^{5} N/C b. 1.68 times10^{5} N/C c. 3.36 times10^{5} N/C d. 4.20 time

Sir Isaac Newton revolutionized science by defining a set of laws to describe the motion of objects. In a 2 to 3 paragraph essay, describe each of Newton’s laws of motion and explain why each is important in understanding planetary motion.

Top fuel drag racer can reach the maximum speed of 304 mph at the end of the 1/4-mile (402 m) racetrack. (a) Assuming that the acceleration is constant during the race, calculate the average value of

A block and a gun are firmly affixed to opposite ends of a long glider mounted on a frictionless air track. The block and gun are a distance L apart. The system is initially at rest. The gun is fired and the bullet leaves the muzzle with a velocity vb and

A person with mass mp = 78 kg stands on a spinning platform disk with a radius of R = 1.5 m and mass md = 198 kg. The disk is initially spinning at w = 1.4 rad/s. The person then walks 2/3 of the way

Identify which of newton’s laws apply to the following situations. 1. When the cannonball is fired through the air (by the explosion), the cannon is pushed backward. 2. Soccer ball will not move until a player kicks it.

A jet lands at 60.2 m/s, the pilot applying the brakes 2.28 s after landing. Find the acceleration needed to stop the jet within 5.83 x 102 m after touchdown. Answer in m/s2.

What is the wavelength (in nm) of radiation that has an energy content of 2.13 x 103 kJ/mol? In which region of the electromagnetic spectrum is this radiation found?

What is the SI unit for intensity?

Mary slides down a snow-covered hill on a large piece of cardboard and then slides across a frozen pond at a constant velocity of +3.0 m/s. After Mary has reached the bottom of the hill and is sliding across the ice, Sue runs after her at a velocity of +

Two teams are involved in a tug-of-war. Why is it wrong to say that the team that pulls the hardest wins? What force really determines who wins?

A quarterback throws a football with an angle of elevation of 40^circ and a speed of 60 ft/s. Find the horizontal and vertical components of the velocity vector.

How do you measure magnetism?

If sunlight shines straight onto a peacock feather, the feather appears blue when viewed from 24 degrees on either side of the incident beam of sunlight. The blue color is due to diffraction from the

Give the values of (n), (l), and (ml) for each orbital in the 4p subshell.

Find the location of the center of mass of three particles with the following masses and coordinates: m_1 has mass 4.0 kg and is located at (x,y) = (4.0 m, 0); m_2 has mass 6.0 kg and is located at (2

Jackie Chan and Matt Damon star in “Some Action Movie.” They realize that a parked car is about to explode. At that point, both Jackie and Matt are standing 2.00 m from the car. Jackie has a faster reaction time and immediately begins running away from th

Authorization

Password generation