If you accelerate magnet along a wire, an emf is induced in a wire because changing magnetic field induces changing electric field and thus electrons in wires are forced to form a current.

So why does'nt shining light on wire induce current in it, considering light is changing magnetic and electric field?

  • $\begingroup$ Which direction would you expect this current to go? $\endgroup$ – The Photon Sep 24 '18 at 13:54
  • $\begingroup$ Wait a second , moving electron experiences a force prependicular to magnetic field , when in a magnetic field , and in the plane of electric field when in electric field , what if these 2 forces are opposite in direction, canceling each other and inducing no current at all ??? @photon Idk can you tell. $\endgroup$ – Rix Vii Sep 24 '18 at 14:11

If you shine light on a piece of metal, it will be absorbed. This absorption is caused by currents induced by the oscillations of the electromagnetic field that make up the light.

Of course, those currents will occur on the same (local) length scale as the light, and on the same (femtosecond) timescale. This means that they're not usable macroscopically.

  • $\begingroup$ So Lets say we use a microphone and send an ANALOUGUE electric signal while shining a light on the wire , would we see noise (INTERFERENCE) on a very accurate calibrated-cro ?? $\endgroup$ – Rix Vii Sep 24 '18 at 10:13
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    $\begingroup$ @Rix They're not easy at all, but there are indeed experiments that measure such currents. $\endgroup$ – Emilio Pisanty Sep 24 '18 at 10:31

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