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Martin, Engineer
Category: General
Satisfied Customers: 4931
Experience:  i'm 41 and i never stopped studying and experimenting
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Unpolarized light with intensity 420 passes first through

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Unpolarized light with intensity 420 passes first through a polarizing filter with its axis vertical, then through a polarizing filter with its axis 23 from vertical. What light intensity emerges from the second filter?
HelloCustomer welcome to Just Answer.

This is known as the Malus law and i will assume perfect polarizer here. The unpolarized light intensity will divide by 2 after the first filter.

After, I = I0 cos^2 teta

I = Intensity after passing the second filter

I0= Intensity between the 2 filter

Teta= angle between the light polarization before the second filter compared to the polarization angle of the second filter.

So, the intensity at the end is 210 cos^2 (23) = 118.

If you replace the angle by 0, you are parallel, so it will give 210 (no attenuation). If you use 90, it will give 0, (complete attenuation).

Martin and 11 other General Specialists are ready to help you
Customer: replied 7 years ago.
Dude your awesome. Thanks
My pleasure. Feedback are always welcome.
Customer: replied 7 years ago.
What information do you need?
Customer: replied 7 years ago.
The answer has to be in mV.
None, all is fine, i just use "info request" so that customers don't click 2 times on accept. I was just mentioning that it's possible to let feedback after you accept an answer. Not an obligation, just nice when someone does.

As for the mV (millivolt?) i don't know how this apply. Light intensity unit is the candela.
Customer: replied 7 years ago.
Are you trying to answer the second question about the magnetic field.
Customer: replied 7 years ago.
The first question about the polarized light, I already recieved. So, I'm good with that answer. Do you need more info on the second question.

A 30-turn, 10-cm-diameter coil is oriented in a vertical plane with its axis aligned east-west. A magnetic field pointing to the northeast decreases from 0.82 T to 0.18 T in 2.3 s. What is the emf induced in the coil?
Sorry, i see, you have another separate question. I can't answer that one as it's not under the general category. I can't answer in the homework category. Someone will get to yo for this one eventually.