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If light ( photons ) of frequency ν < sub > 12 </ sub > pass through the group of atoms, there is a possibility of the light being absorbed by atoms which are in the ground state, which will cause them to be excited to the higher energy state.
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If and light
If she did, he could stand it better in the light.
If the input light distribution falls beyond the visible range, Af as expected, since Af.
If it pleases symphony audiences as a light, jolly piece, a series of impressions musically expressed, it succeeds.
If light moves instantaneously, the telescope does not move, and the true direction of the star relative to the observer can be found by following the line ES.
If, in an unsharp image, a patch of light corresponds to an object point, the center of gravity of the patch may be regarded as the image point, this being the point where the plane receiving the image, e. g., a focusing screen, intersects the ray passing through the middle of the stop.
If appropriate proportions of three primary pigments are mixed, the result reflects so little light as to be called " black ".
If the source emits light uniformly in all directions, the flux can be found by multiplying the intensity by 4π: a uniform 1 candela source emits 12. 6 lumens.
If it is removed, the light ceases.
If the glass is cooled quickly in the absence of a strong light source by putting ice on the glass or placing it in the freezer with the door almost closed, it turns backwards ( i. e. the silver sides trail ).
If light pressure were the cause of the rotation, then the better the vacuum in the bulb, the less air resistance to movement, and the faster the vanes should spin.
If the incident light is monochromatic, these sources all have the same phase.
If light consisted strictly of ordinary or classical particles, and these particles were fired in a straight line through a slit and allowed to strike a screen on the other side, we would expect to see a pattern corresponding to the size and shape of the slit.
If the width of the slits is small enough ( less than the wavelength of the laser light ), the slits diffract the light into cylindrical waves.
If the width of the slits is greater than the wavelength, the Fraunhofer diffraction equation gives the intensity of the diffracted light as:
If a ray tracing is then made as if a light wave ( as understood in classical physics ) is wide enough to take both paths, then that ray tracing will accurately predict the appearance of maxima and minima on the detector screen when many particles pass through the apparatus and gradually " paint " the expected interference pattern.
If the emulsion is dilute enough, higher-frequency and low-wavelength light will be scattered more, and the emulsion will appear bluer-this is called the " Tyndall effect ".
If applied to optical wavelengths, this manifests itself as a change in the colour of visible light as the wavelength of the light is increased toward the red part of the light spectrum.
If the incident light is unpolarised ( containing an equal mix of s-and p-polarisations ), the reflection coefficient is
If a laser is swept across a distant object, the spot of laser light can easily be made to move across the object at a speed greater than c. Similarly, a shadow projected onto a distant object can be made to move across the object faster than c. In neither case does the light travel from the source to the object faster than c, nor does any information travel faster than light.
If Lorentz symmetry can cease to be a fundamental symmetry at Planck scale or at some other fundamental scale, it is conceivable that particles with a critical speed different from the speed of light be the ultimate constituents of matter.
If and photons
If the photons reside mainly in the higher index material, the confinement is due to total internal reflection.
If the number of photons being amplified per unit time is greater than the number of photons being absorbed, then the net result is a continuously increasing number of photons being produced ; the laser medium is said to have a gain of greater than unity.
If the ground state has a higher population than the excited state ( N < sub > 1 </ sub > > N < sub > 2 </ sub >), the process of absorption dominates and there is a net attenuation of photons.
If we imagine the beam is made of photons, then every second numerous photons strike the surface and are absorbed.
If the light were totally reflected then the radiation pressure is doubled compared to total absorption, this is because the photons arrive with momentum E / c and depart with momentum-E / c ( the-ve sign indicates traveling in the opposite direction ), so the change of momentum is 2E / c.
If light falling on the device is of high enough frequency, photons absorbed by the semiconductor give bound electrons enough energy to jump into the conduction band.
If the bandgap is too high, most daylight photons cannot be absorbed ; if it is too low, then most photons have much more energy than necessary to excite electrons across the bandgap, and the rest is wasted.
Prior to any measurements being made, the polarizations of the photons are indeterminate ; If a measurement is made on one of the photons using a two-channel polarizer aligned with the axes of the coordinate system, the photon assumes either horizontal or vertical polarization, with 50 % probability for each orientation, and the other two photons immediately assume the identical polarization.
If photons of a particular wavelength are absorbed by matter, then when we observe light reflected from or transmitted through that matter, what we see is the complementary color, made up of the other visible wavelengths remaining.
If the photons are formed by the collision of a particle and an antiparticle, the invariant mass is the same as the total energy of the particle and antiparticle ( their rest energy plus the kinetic energy ), in the center of mass frame, where they will automatically be moving in equal and opposite directions ( since they have equal momentum in this frame ).
If the photons are formed by the disintegration of a single particle with a well-defined rest mass, like the neutral pion, the invariant mass of the photons is equal to rest mass of the pion.
If the Universe is dominated by radiation, or by dark energy, though, those potentials do evolve, subtly changing the energy of photons passing through them.
If their main purpose is radiation measurement, they are called radiation detectors, but as photons are also ( massless ) particles, the term particle detector is still correct.
If this is the case, some or all of the photons emitted by the fluorophore may be absorbed again.
If a Dp-brane is embedded in a spacetime of d spatial dimensions, the brane carries ( in addition to its Maxwell field ) a set of d-p massless scalars ( particles which do not have polarizations like the photons making up light ).
If the optical filter passed only that frequency band, then there would be a net transfer of photons, and their energy, from the second system to the first.
If this were true however, the radiometer would spin away from the non-black faces, since the photons bouncing off those faces impart even more momentum than the photons absorbed on the black faces.
If and frequency
If one eigenvalue is negative ( i. e., an imaginary frequency ), then the stationary point is a transition structure.
If measured instead per unit wavelength, using Wien's law, the peak is at 1. 06 mm corresponding to a frequency of 283 GHz.
If frequency-hopping is avoided, each base station can provide up to 120 channels in the DECT spectrum before frequency reuse.
If the two input signals are both sinusoids of specified frequencies f < sub > 1 </ sub > and f < sub > 2 </ sub >, then the output of the mixer will contain two new sinsoids that have the sum f < sub > 1 </ sub > + f < sub > 2 </ sub > frequency and the difference frequency absolute value | f < sub > 1 </ sub >-f < sub > 2 </ sub >|.
If the two signals are close together in frequency the heterodyne is low enough to be measured by a frequency counter.
If the baseband data signal ( the message ) to be transmitted is and the sinusoidal carrier is, where f < sub > c </ sub > is the carrier's base frequency and A < sub > c </ sub > is the carrier's amplitude, the modulator combines the carrier with the baseband data signal to get the transmitted signal:
If the frequency deviation is held constant and the modulation frequency increased, the spacing between spectra increases.
If the wavepacket has a relatively large frequency spread, or if the dispersion has sharp variations ( such as due to a resonance ), or if the packet travels over very long distances, this assumption is not valid.
If the length of the intervals on the x-axis are all 1, then a histogram is identical to a relative frequency plot.
If F is the only force acting on the system, the system is called a simple harmonic oscillator, and it undergoes simple harmonic motion: sinusoidal oscillations about the equilibrium point, with a constant amplitude and a constant frequency ( which does not depend on the amplitude ).
If a crest of a wave meets a crest of another wave of the same frequency at the same point, then the magnitude of the displacement is the sum of the individual magnitudes – this is constructive interference.
If the pump waves are of frequency ω < sub > 1 </ sub >
If two waves of the same wavelength and frequency are in phase, both the wave crests and wave troughs align.
If surviving Linear B clay tablets can be trusted, the name po-se-da-wo-ne (" Poseidon ") occurs with greater frequency than does di-u-ja (" Zeus ").
If an atom is already in the excited state, it may be perturbed by the passage of a photon that has a frequency ν < sub > 21 </ sub > corresponding to the energy gap ΔE of the excited state to ground state transition.
If we now subject the atoms to light of a frequency, the process of optical absorption will excite the atoms from the ground state to level 3.
If the object is moving either toward or away from the transmitter, there is a slight equivalent change in the frequency of the radio waves, caused by the Doppler effect.
If λ represents wavelength and f represents frequency ( note, λf = c where c is the speed of light ), then z is defined by the equations:
If an object moves with angular velocity ω around a circle of radius r centered at the origin of the x-y plane, then its motion along each coordinate is simple harmonic motion with amplitude r and angular frequency ω.
If the BFO frequency is off, the output signal will be frequency-shifted ( up or down ), making speech sound strange and " Donald Duck "- like, or unintelligible.
If is off by a small amount, then the beat frequency is not exactly, which can lead to the speech distortion mentioned earlier.
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