When Casey looks at a CD or DVD she notices that there is a rainbow pattern that is created by the light. She became curious and
shone light directly at it and a pattern was created on the wall. What is the cause of this pattern?
2 answers:
Answer:
Interference
Explanation:
A CD is made up of thousands of pits arranged in the form of spiral tracks.These repeated patterns of pits form a thin film.
This film has the thickness of the order of the wavelength of the light which causes the interference of the waves of the light waves. The incident ray of light gets reflected from the top layer of the film partially and then after striking the bottom layer of the film creating a phase difference responsible for the constructive and destructive interference.
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Answer:
speed, distance and direction of motion of the object can be determined by analyzing the radio wave.
Explanation:
We know that radar operates by transmitting radio waves to a destination and these waves are comes back to the receiver station. By Considering this transmission and receiver process, we can measure the distance, velocity and path of an object's movement.
Distance can be assessed by taking following consideration, the velocity of the waves is V. It can help to assess the time made for the waves to be emitted by the radar and felt by the receiver, let the time be t.
Therefore distance can be determine as D= v*t/2,
here 2 signifies that the distance travelled by the wave in either direction ( from transmitter to receiver and vice verse)
Using the source wave frequency, speed can be computed. In a specific frequency, the radar starts sending out the frequencies and the reflected wave will have a distinct frequency. The velocity can be determine by
whereis the change in frequency and
c is the speed of light (the wave).
Direction can be determine by applying above principle. change in frequency is used to determine the direction in the following way:
When the frequency transition is very low, the object moves away from the radar and vice verse.
Answer:
<h2>The current required winding isExplanation:
We can use the expression B=μ₀*n*I-------1 for the magnetic field that enters a coil and
n= N/L (number of turns per unit length)
Given data
The number of turns n= 1200 turns
length L= 0.42 m
magnetic field B= 1*10^-4 T
μ₀=
Applying the equation B=μ₀*n*I
I= B/μ₀*n
I= B*L/μ₀*n