The correct answer of this question is : A) Change alternating current into direct current.
EXPLANATION :
As per the question, we are given vacuum tube. Vacuum tube can be of various types. Normally it contains two electrodes called cathode and anode which are enclosed in an evacuated glass chamber . There are also other types of vacuum tubes which contain extra electrodes like control grid .
The vacuum tube can be used as a rectifier. It means that it can be used as an electronic device which will convert alternating current into direct current. It may be a half wave rectifier or a full wave rectifier. Actually the direct current obtained during the rectification of alternating current is pulsating in nature.
Hence, the correct answer is that a vacuum tube can be used to change alternating current into direct current.
The answer is magnet away from the coil
Answer:
Explanation:
Acceleration is given by
where
u is the initial velocity
v is the final velocity
t is the time interval
In this problem:
is the initial velocity
is the final velocity
t = 2 s is the time
Substituting, we find the acceleration:
Both objects have the same electrical charge. Opposite charges attract. And if they were neutral they would not do anything.
Answer:
t< 75 nm
Explanation:
A soap bubble is a thin film where when the beam enters the film it has a 180º phase change due to the refractive index and the wavelength changes between
λ = λ₀ / n
In the case of constructive interference in the curve of the spherical film it is
2 nt = (m + ½) λ₀
Where t is the thickness of the film and n the refractive index that does not indicate that we use that of water n = 1.33, m is an integer. The thickness of the film for the first interference (m = 0) is
t = λ₀ / 4 n
A thickness less than this gives destructive interference.
Let's look for the thickness for the visible spectrum
Violet light λ₀ = 400 nm = 400 10⁻⁹ m
t₁ = 400 10⁻⁹ / 4 1.33
t₁ = 75.2 10-9 m
Red light λ₀ = 700 nm = 700 10⁻⁹ m
t₂ = 700 10⁻⁹ / 4 1.33
t₂ = 131.6 10⁻⁹ m
Therefore, for all wavelengths to have destructive interference, the thickness must be less than 75 10⁻⁹ m = 75 nm
b) a film like eta is very thin, it is achieved when gravity thins the pomp, but any movement or burst of air breaks it,
