Answer:
The current in the solenoid=0.463 Ampere
Explanation:
Given:
Number of turns , N=420
Length of the solenoid=0.575 m
Magnitude of Magnetic Field,
We know that the magnitude of the magnetic Field inside the solenoid is
Where
is the permeability of free space.- n is the number of turns per unit length
- i is the current
According to question
Hence the current is calculated.
C. Sonography
Sonography makes use of sound waves.
Answer: Because of Inertia
Explanation: According to Newton first law, that a body in a linear motion will continue to be in motion except an external for act on it
But also, a body in motion will always like to continue in motion and have a reluctance tendency to stop because of inertia.
the crash test dummies' bodies will continue to move forward even though the car stopped because of inertia.
To solve this problem we will apply the concepts related to the Doppler Effect. The Doppler effect is the change in the perceived frequency of any wave movement when the emitter, or focus of waves, and the receiver, or observer, move relative to each other.
Mathematically it can be described as
Where,
v = Speed of sound
f' = Reflected frequency
f = Emitted Frequency
= Speed of the object
Assuming that the speed of the medium is the speed of sound of 343m / s, we will then have that:
-A photon travels, on average, a particular distance, d, before being briefly absorbed and released by an atom, which scatters it in a new random direction.
-Given d and the speed of light, c, you can figure out the average time step and space step size (how often the photon “steps” and how far it “steps” each time).
-The size of the Sun is figured in terms of step size. Some surprisingly tricky math happens, involving “Brownian motion” and probabilities. Finally,
-The average time it would take to get to the surface of the Sun is found.
