Explanation:
We know that a changing magnetic field induces a current in a conductor. For that reason a generator basically consist an element that produces a magnetic field that changes over time and a conductor where the current will be induced.
This element that produces a magnetic field can be one of the following:
- A permanent magnet: Which is basically like a regular magnet. The magnetic field that a permanent magnet produces does not change over time, we need a motor or any other external force to move the axis of the generator and cause the magnetic field to change.
- An electro-magnet. Which is basically a DC current flowing through a conductor. Basically, when current flows through a conductor it behaves exactly like a magnet. So what we commonly do, is to connect a conductor to a DC battery, and it will create a magnetic field.
Like we are using a DC battery to create a magnetic field, then the magnetic field won't change over time either. So we still need an external force to move the axis of the generator to produce AC electricity.
The length of a wave so, therefore its D.
The correct answer is 432, and 720.
The thickness of a film is t= 360nm
the refractive index of oil n₀t = (m +1/2) λ
For m =0
λ = 4n₀t
= 4(1.50)(360)
= 2160nm
for m = 1
λ = 4n₀t
= 4(1.50)(360)/3
= 720nm
m = 2
λ = 4n₀t/5 = 4(1.50)(360)/5
= 432nm
The wavelength which are most strongly reflected are
432nm, 720nm.
The interstellar medium is the matter as well as the radiations that are found in the galaxies occupying the spaces between the star systems.
Interstellar medium is mainly composed of hydrogen that is followed by helium and trace amounts of nitrogen, oxygen and carbon (considered traces when compared to amount of hydrogen).
Therefor, the right choice is:
<span>A. Water, Carbon dioxide, and Hydrogen</span>
