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Anika [276]
3 years ago
5

A monochromatic red laser beam emitting 1 mW at a wavelength of 638 nm is incident on a silicon solar cell. Find the following:

a. The number of photons per second incident on the cell b. The maximum possible efficiency of conversion of this laser c. beam to electricity
Physics
1 answer:
tia_tia [17]3 years ago
8 0

Answer:

Explanation:

First we calculate the energy of the photon

E=(Planck constant × speed of light in vacuum)÷ wave length

E=\frac{6.626*10^{34}*2.998*10^{8}  }{638*10^{-9} } = 3.114*10^{49}

Next we find the total energy per second

total energy= 1*10^{-3}W *\frac{1JS^{-1} }{1W}  = 1*10^{-3} JS^{-1}

Next we calculate the number the photon per second

= total energy ÷ energy of 1 photon

= \frac{1*10^{-3} JS^{-1}  }{3.114*10^{49} } =  3.21*10^{-53}  \ photons/sec

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All electric circuits have devices that are run by _____ energy.
KATRIN_1 [288]

Answer: electrical energy

Explanation:

Electrical energy

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3 years ago
A wave has a wavelength of 3.3 m and a speed of 5.6 m/s. What is the frequency of this wave
nikitadnepr [17]

Answer: λ (wavelength) = 3.3 m →  ΔS = 3.3 m

v (speed) = 5.6 m/s → ΔV = 5.6 m/s

T (period) → ΔT = ?

f (frequency) = ?

If:

Now: (if, ΔT = T), Using the formula of the period of a wave, find the frequency:

Explanation: Your Welcome u.u

5 0
2 years ago
11 kg is a familiar weight for a bag of flour. You are baking cookies for a Save The Rain Forest fund drive. It takes 500 g of f
arlik [135]

Answer: 22 batches.

Explanation:

Given that 11 kg is a familiar weight for a bag of flour. Also, it is given that It takes 500 g of flour to make one batch of cookies.

How many batches of cookies can you make with one bag of flour

Let's first convert 11 kg into grams (g) by multiplying it by 1000

11 × 1000 = 11000 g

Divide 11000 by 500

11000/500 = 22

Therefore, 22 batches of cookies can be made with one bag of flour.

8 0
3 years ago
A string exerts a force of 20 N on a box at an angle of 38° from the horizontal. What is the horizontal
Gnoma [55]

Answer:

15.76N

Explanation:

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4 0
2 years ago
Read 2 more answers
An inductor in an LC circuit has a maximum current of 2.4 A and a maximum energy of 56 mJ.
Harrizon [31]

Answer:

The energy stored in the capacitor, when the current in the inductor is 1.2 A, is 41.6 mJ.

Explanation:

In a LC oscillating circuit, the energy is stored in the electric field (between the plates of the capacitor) and in the magnetic field (surrounding the wires of the inductor).

At any time, the sum of both energies can be expressed as follows:

E = 1/2 Q² / C   +  1/2 L I²

In this type of circuit, energy oscillates, which means that it is exchanging between both fields all time.

When the capacitor is completely discharged, all the energy is stored in the magnetic field, and at that time, the current is maximum.

The total energy, when I is maximum, can be written as follows:

E = 1/2 L I² (1)

In our case, when I= 2.4A, E= 56 mJ.

So, we can find out the value of L, which will allow us to know the value of the magnetic energy at any time, having the value of the instantaneous current.

Solving for L in (1):

L = 2 *.56 mJ / (2.4)² A² = 20 mH

The next step is getting the value of the energy stored in the inductor, when I = 1.2 A, as follows:

Em = 1/2 *20 mH.* (1.2)² A² = 14.4 mJ

As the total energy must be always the same, i.e., 56 mJ, the energy stored in the capacitor, assuming no losses, must be the difference between the total energy and the one stored in the magnetic field:

Ec = 56 mJ - 14.4 mJ = 41.6 mJ

3 0
3 years ago
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