The energy of a single photon at the transmitted frequency is
Answer: Option b
<u>Solution:</u>
Energy of photon is given as
Where c is the velocity of Light
h is planck's constant
λ is the wavelength of photon
Energy of photon can be rewritten as
Where f is the frequency of photon
Frequency of photon is obtained by dividing velocity of light by wavelength of photon.
car starts from rest
final speed attained by the car is
acceleration of the car will be
now the time to reach this final speed will be
so it required 1.39 s to reach this final speed
To answer the problem we would be using this formula which is I(peak) = P(peak)/(4πd^2) = 4.24413181578388 w/m^2
E = sqrt(I(peak)*Z0) = 39.9861614728793 V/m
B = µ0*sqrt(I(peak)/Z0) = 1.33379477721328E-7 T
(Free-space impedance Z0 = sqrt(µ0/e0) = 376.730313462204 ohms)
D = 497.4x10⁻⁶m. The diameter of a mile of 24-gauge copper wire with resistance of 0.14 kΩ and resistivity of copper 1.7×10−8Ω⋅m is 497.4x10⁻⁶m.
In order to solve this problem we have to use the equation that relates resistance and resistivity:
R = ρL/A
Where ρ is the resistivity of the matter, the length of the wire, and A the area of the cross section of the wire.
If a mile of 24-gauge copper wire has a resistance of 0.14 kΩ and the resistivity of copper is 1.7×10⁻⁸ Ω⋅m. Determine the diameter of the wire.
First, we have to clear A from the equation R = ρL/A:
A = ρL/R
Substituting the values
A = [(1.7×10⁻⁸Ω⋅m)(1.6x10³m)]/(0.14x10³Ω)
A = 1.9x10⁻⁷m²
The area of a circle is given by A = πr² = π(D/2)² = πD²/4, to calculate the diameter D we have to clear D from the equation:
D = √4A/π
Substituting the value of A:
D = √4(1.9x10⁻⁷m²)/π
D = 497.4x10⁻⁶m